Methods and apparatus for determining, communicating and using information including loading factors which can be used for interference control purposes

ABSTRACT

A wireless terminal receives and measures broadcast reference signals, e.g., beacon and/or pilot signals, transmitted from a plurality of base station attachment points. The wireless terminal monitors for and attempts to recover broadcast loading factor information corresponding to attachment points. The wireless terminal generates and transmits an interference report to a current attachment point, the report based on the results of a measured received reference signal from the current attachment point, a measured received reference signal from each of one or more different attachment points, and uplink loading factor information. In the absence of a successfully recovered broadcast uplink loading factor corresponding to an attachment point, the wireless terminal uses a default value for that loading factor. Generated interference reports are based on beacon signal measurements and uplink loading factors, pilot signal measurements and uplink loading factors, or a mixture of beacon and pilot signal measurements and uplink loading factors.

RELATED APPLICATIONS

The present application claims the benefit of the filing date of U.S.Provisional Patent Application Ser. No. 60/792,128, filed on Apr. 14,2006 titled “METHODS AND APPARATUS FOR DETERMINING, COMMUNICATING ANDUSING INFORMATION WHICH CAN BE USED FOR INTERFERENCE CONTROL PURPOSES”and is a continuation in part of U.S. patent application Ser. No.11/251,069 filed Oct. 14, 2005, which claims priority to ProvisionalApplication No. 60/618,773 filed Oct. 14, 2004, and is a continuation inpart of U.S. patent application Ser. No. 11/302,729 filed Dec. 14, 2005,each of which is hereby expressly incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to wireless communications system and,more particularly, to method and apparatus for collecting, measuring,reporting and/or using information which can be used for interferencecontrol purposes in a wireless communications system.

BACKGROUND

In a wireless multiple access communication system, wireless terminalscontend for system resources in order to communicate with a commonreceiver over an uplink channel. An example of this situation is theuplink channel in a cellular wireless system, in which wirelessterminals transmit to a base station receiver. When a wireless terminaltransmits on the uplink channel, it typically causes interference to theentire system, e.g., neighboring base station receivers. Since wirelessterminals are distributed, controlling the interference generated bytheir transmission is a challenging problem.

Many cellular wireless systems adopt simple strategies to control uplinkinterference. For example CDMA voice systems (e.g., IS-95) power controlwireless terminals in such a manner that their signals are received atthe base station receiver at approximately the same power.State-of-the-art CDMA systems such as 1xRTT and 1xEV-DO allow forwireless terminals to transmit at different rates, and be received atthe base station at different powers. However, interference iscontrolled in a distributed manner which lowers the overall level ofinterference without precisely controlling those wireless terminals thatare the worst sources of interference in the system.

This existing body of interference-control approaches limits the uplinkcapacity of wireless systems.

It would be useful if a base station could be provided with informationthat could be used in determining the amount of signal interference thatwill be created in neighboring cells and/or sectors when a transmissionoccurs and/or determining the amount of interference a wireless terminalis likely to encounter due to signal interference. It would beparticularly desirable if information which can be used for interferencedetermination purposes could be supplied by one or more wirelessterminals to a base station.

Loading affects interference considerations in a wireless communicationssystem. It would be beneficial if wireless terminals and/or basestations communicated such information. It would also be beneficial ifwireless terminals and/or base stations utilized such loadinginformation in determining interference levels.

Various received different types of downlink broadcast reference signalsmay be usable at different times to a wireless terminal which is tocommunicate interference information to a base station. It would bebeneficial if methods and apparatus supported utilizing different typesof broadcast reference signals in determining interference informationand/or tailoring the reporting calculations to accommodate a current setof conditions.

SUMMARY

Various embodiments are directed to methods and apparatus forcollecting, measuring, reporting and/or using information which can beused for interference control purposes.

In accordance with various embodiments, wireless terminals, e.g., mobilenodes, measure reference signals transmitted from one or more basestations, e.g., base station sector attachment point transmitters. Themeasured reference signals may be, e.g., beacon signals and/or pilotsignals. The beacon signals may be narrowband signals, e.g., a singletone. The beacon signals may have a duration of one, two or more symboltransmission time periods, e.g., OFDM symbol transmission time periods.However, other types of beacon signals may be used and the particulartype of beacon signal is not critical to the invention. From themeasured reference signals, the wireless terminal generates, in someembodiments, one or more gain ratios which provide information about therelative gain of the communications channels from different base stationsectors to the wireless terminal. Uplink base station attachment pointloading factor information corresponding to one or more different basestation attachment points is, in some embodiments, also used indetermining interference information.

Based on the signal energy measurements, relative gains generated fromthe energy measurements, and uplink loading factor information reportsare generated and sent to one or more base stations, e.g., a beaconratio report is generated and sent to current serving connection basestation attachment point using a dedicated control channel. The reports,e.g. uplink interference reports such as beacon ratio reports, may be ina plurality of different formats and may provide information relating acurrent serving base station attachment point to a single one additionalbase station attachment point or to multiple additional base stationattachment points. A current serving base station sector attachmentpoint may request from a wireless terminal transmission of aninterference report providing interference information relating to aspecific different base station sector attachment point, e.g., anadjacent cell and/or sector base station sector attachment point. Thisis done, in some embodiments, by the current serving base station sectorattachment point transmitting a request for a specific interferencereport to the wireless terminal. The request normally identifies, eitherdirectly or indirectly, the interfering BS sector attachment point forwhich the specific report is sought. The wireless terminal will respondto such a request by transmitting the requested report.

In addition to responding to requests for specific interference reports,wireless terminals, in some embodiments, transmit interference reportsgenerated according to a reporting schedule. In such embodiments, a basestation sector attachment point having an active connection with awireless terminal will receive interference reports on a predictable,e.g., predetermined, schedule, e.g., as part of a recurring dedicatedcontrol channel reporting schedule.

Depending on the embodiment, generation of gain ratios and/or reportsmay be a function of various factors indicative of relative transmissionpower levels used by different base station sector attachment pointsand/or for different signals which may be measured. In this manner,signals which are transmitted at different power levels, e.g., pilotsand beacon signals, can be measured and used in generating reliablerelative channel gain estimates by taking into consideration thedifferent relative transmission power levels of the various signalsbeing measured.

As discussed above, a wireless terminal receives and measures broadcastreference signals, e.g., beacon and/or pilot signals, transmitted from aplurality of base station attachment points. The wireless terminalmonitors for and attempts to recover broadcast loading factorinformation corresponding to base station attachment points. In someembodiments, uplink loading factor information corresponding to a basestation attachment point is communicated in a downlink broadcast reportwhich conveys one of at least 4 different loading levels. In one suchembodiment the uplink loading factor corresponding to a base stationattachment point is communicated in a 3 bit report communicating one ofeight loading levels. In some embodiments an uplink loading factorreport corresponding to a particular base station attachment point iscommunicated via a downlink broadcast from the same particular basestation attachment point to which the uplink loading factor reportcorresponds. In some embodiments, a base station sector attachmentpoint, e.g., a current serving connection base station sector attachmentpoint broadcasts uplink loading factor information corresponding to aplurality of local base station sector attachment points. In such anembodiment, a wireless terminal synchronized with respect to its currentserving base station attachment point is able to recover and use uplinkloading factor information corresponding to other local base stationsector attachment points of interest, even though the wireless terminalmay not be timing synchronized with respect to those additional basestation attachment points and/or the broadcast control signalscommunicating uplink load factor information transmitted from thoseadditional base station attachments points may be too weak from thewireless terminal's perspective to be otherwise recovered.

The wireless terminal generates and transmits an interference report toa current base station attachment point, the report based on the resultsof a measured received reference signal from the current base stationattachment point, a measured received reference signal from each of oneor more different base station attachment points, and uplink loadingfactor information. In the absence of a successfully recovered broadcastuplink loading factor corresponding to a base station attachment pointto be used in the interference report, the wireless terminal uses adefault value for the loading factor corresponding to the base stationattachment point.

Generated interference reports, in various embodiments, are based onbeacon signal measurements and uplink loading factors, pilot signalmeasurements and uplink loading factors, or a mixture of beacon andpilot signal measurements and uplink loading factors. Transmission gainfactors relating one reference signal to another are used, in someembodiments, by the wireless terminal in generating an interferencereport. For example, in one exemplary embodiment, beacon signals aretransmitted at the same power levels throughout the system, and pilotsignals are transmitted at different levels in the system, with thepilot signals from a particular attachment point being transmitted atone of a plurality of predetermined power tier levels. A wirelessterminal utilizes transmission gain adjustment factors, when needed, incomparing received reference signals of different types and/or sourcedfrom different attachment points. In addition, the wireless terminaluses received and/or default base station attachment point uplinkloading factors in scaling received reference signal power levels andgenerating an interference report.

One type of interference report, e.g., a specific interference report,sometimes otherwise referred to as a special interference report,relates a current serving base station attachment point to a singleadditional base station attachment point, and, in various embodiments,multi-level uplink loading factors are used in generating the report. Insome such embodiments, the single additional base station attachmentpoint is selected by the current serving base station attachment point.Another type of interference report, e.g., a generic interferencereport, relates a current serving base station attachment point to oneor more additional base station attachment points, is generated usingone of a summing function and a maximum function and, in someembodiments, is generated utilizing multi-level uplink loading factorinformation.

While various embodiments have been discussed in the summary above, itshould be appreciated that not necessarily all embodiments include thesame features and some of the features described above are not necessarybut can be desirable in some embodiments. Numerous additional features,embodiments and benefits of the present invention are discussed in thedetailed description which follows.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing of an exemplary wireless communications systemimplemented in accordance with various embodiments.

FIG. 2 shows an example of a base station implemented in accordance withvarious embodiments.

FIG. 3 illustrates a wireless terminal implemented in accordance withvarious embodiments.

FIG. 4 illustrates a system in which a wireless terminal is connected toa base station sector and measures the relative gains associated with aplurality of interfering base stations in accordance with variousembodiments.

FIG. 5 is a flow chart illustrating a method of measuring signal energy,determining gains and providing interference reports in accordance withvarious embodiments.

FIG. 6 illustrates an uplink traffic channel and segments includedtherein.

FIG. 7 illustrates assignments which can be used by a base station toassign uplink traffic channel segments to a wireless terminal.

FIG. 8 shows an exemplary communication system implemented in accordancewith various embodiments.

FIG. 9 includes exemplary power scaling factor table, implemented inaccordance with the present invention.

FIG. 10 includes an exemplary uplink loading factor table used invarious embodiments in the generation of interference reports.

FIG. 11 is a table illustrating an exemplary format for an exemplaryinterference report, e.g., a beacon ratio report, in accordance withvarious embodiments.

FIG. 12 is a drawing of an exemplary orthogonal frequency divisionmultiplexing (OFDM) wireless communications system, e.g., an OFDM spreadspectrum multiple access wireless communications system, implemented inaccordance with various embodiments.

FIG. 13 illustrates the exemplary system of FIG. 12, and providesadditional detail corresponding to each of the base station sectors toillustrate various features.

FIG. 14 is a drawing of the exemplary system described in FIGS. 12 and13, which includes exemplary signaling received and processed by awireless terminal for the purposes of illustrating exemplary beaconratio report methods in accordance with various embodiments.

FIG. 15 is a drawing of the exemplary system, described in FIGS. 12 and13, which includes exemplary signaling received and processed by awireless terminal for the purposes of illustrating exemplary beaconratio report methods in accordance with various embodiments.

FIG. 16 is a drawing of the exemplary system, described in FIGS. 12 and13, which includes exemplary signaling received and processed by awireless terminal for the purposes of illustrating exemplary beaconratio report methods in accordance with various embodiments.

FIG. 17, comprising the combination of FIG. 17A, FIG. 17B, FIG. 17C, andFIG. 17D is a flowchart of an exemplary method of operating a wirelessterminal, e.g., mobile node, in accordance with various embodiments.

FIG. 18 is a drawing of exemplary timing structure information andcorresponding interference reporting information, e.g., beacon ratioreport reporting information, for an exemplary embodiment.

FIG. 19 illustrates in drawing, for an exemplary embodiment, exemplarybeacon ratio report request downlink signaling and exemplary uplinkbeacon ratio report signaling.

FIG. 20 is a drawing of an exemplary communications system implementedin accordance with various embodiments.

FIG. 21 is a drawing illustrating exemplary downlink control signalingand uplink interference reporting, e.g., beacon ratio reporting,corresponding to the exemplary system of FIG. 20.

FIG. 22 is a drawing of a flowchart of an exemplary method of operatinga wireless terminal in accordance with various embodiments.

FIG. 23 is a drawing of an exemplary wireless terminal implemented inaccordance with various embodiments.

FIG. 24 comprising the combination of FIG. 24A and FIG. 24B is aflowchart of an exemplary method of operating a wireless terminal.

FIG. 25, comprising the combination of FIG. 25A and FIG. 25B is aflowchart of an exemplary method of operating a wireless terminal inaccordance with various embodiments.

FIG. 26 is a drawing of a table illustrating exemplary interferencereport signal usage and report computations in accordance with variousembodiments.

FIG. 27 is a drawing of an exemplary wireless terminal implemented inaccordance with various embodiments.

DETAILED DESCRIPTION

Methods and apparatus for collecting, reporting and using informationwhich can be used for interference control purposes in accordance withvarious embodiments will now be described. The methods and apparatus ofthe present invention are well suited for use with wireless multipleaccess, e.g., multi-user, communications systems. Such systems may beimplemented as OFDM systems, CDMA systems or other types of wirelesssystems where signal interference from transmission from one or moretransmitters, e.g., adjacent base stations, is of concern.

An exemplary embodiment of the invention is described below in thecontext of a cellular wireless data communication system 100 of thepresent invention shown in FIG. 1. While an exemplary cellular wirelesssystem is used for purposes of explaining the invention, the inventionis broader in scope than the example and can be applied in general tomany other wireless communication systems as well.

In a wireless data communication system, the air link resource generallyincludes bandwidth, time or code. The air link resource that transportsuser data and/or voice traffic is called the traffic channel. Data iscommunicated over the traffic channel in traffic channel segments(traffic segments for short). Traffic segments may serve as the basic orminimum units of the available traffic channel resources. Downlinktraffic segments transport data traffic from the base station to thewireless terminals, while uplink traffic segments transport data trafficfrom the wireless terminals to the base station. One exemplary system inwhich the present invention may be used is the spread spectrum OFDM(orthogonal frequency division multiplexing) multiple-access system inwhich, a traffic segment includes a number of frequency tones definedover a finite time interval.

FIG. 1 is an illustration of an exemplary wireless communications system100, implemented in accordance with various embodiments. Exemplarywireless communications system 100 includes a plurality of base stations(BSs): base station 1 102, base station M 114. Cell 1 104 is thewireless coverage area for base station 1 102. BS 1 102 communicateswith a plurality of wireless terminals (WTs): WT(1) 106, WT(N) 108located within cell 1 104. WT(1) 106, WT(N) 108 are coupled to BS 1 102via wireless links 110, 112, respectively. Similarly, Cell M 116 is thewireless coverage area for base station M 114. BS M 114 communicateswith a plurality of wireless terminals (WTs): WT(1′) 118, WT(N′) 120located within cell M 116. WT(1′) 118, WT(N′) 120 are coupled to BS M114 via wireless links 122, 124, respectively. WTs (106, 108, 118, 120)may be mobile and/or stationary wireless communication devices. MobileWTs, sometimes referred to as mobile nodes (MNs), may move throughoutthe system 100 and may communicate with the base station correspondingto the cell in which they are located. Region 134 is a boundary regionbetween cell 1 104 and cell M 116. In the FIG. 1 system, the cells areshown as single sector cells. Multi-sectors cells are also possible andare supported. The transmitter of a base station sector can beidentified based on transmitted information, e.g., beacon signals, whichcommunicate a base station identifier and/or sector identifier.

Network node 126 is coupled to BS 1 102 and BS M 114 via network links128, 130, respectively. Network node 126 is also coupled to othernetwork nodes/Internet via network link 132. Network links 128, 130, 132may be, e.g., fiber optic links. Network node 126, e.g., a router node,provides connectivity for WTs, e.g., WT(1) 106 to other nodes, e.g.,other base stations, AAA server nodes, Home agents nodes, communicationpeers, e.g., WT(N′), 120, etc., located outside its currently locatedcell, e.g., cell 1 104.

FIG. 2 illustrates an exemplary base station 200, implemented inaccordance with various embodiments. Exemplary BS 200 may be a moredetailed representation of any of the BSs, BS 1 102, BS b 114 of FIG. 1.BS 200 includes a receiver 202, a transmitter 204, a processor, e.g.,CPU, 206, an I/O interface 208, I/O devices 210, and a memory 212coupled together via a bus 214 over which the various elements mayinterchange data and information. In addition, the base station 200includes a receiver antenna 216 which is coupled to the receiver 202 anda transmitter antenna 218 which is coupled to transmitter 204.Transmitter antenna 218 is used for transmitting information, e.g.,downlink traffic channel signals, beacon signals, pilot signals,assignment signals, interference report request messages, interferencecontrol indicator signals, etc., from BS 200 to Wts 300 (see FIG. 3)while receiver antenna 216 is used for receiving information, e.g.,uplink traffic channel signals, WT requests for resources, WTinterference reports, etc., from WTs 300.

The memory 212 includes routines 220 and data/information 224. Theprocessor 206 executes the routines 220 and uses the data/information224 stored in memory 212 to control the overall operation of the basestation 200 and implement methods. I/O devices 210, e.g., displays,printers, keyboards, etc., display system information to a base stationadministrator and receive control and/or management input from theadministrator. I/O interface 208 couples the base station 200 to acomputer network, other network nodes, other base stations 200, and/orthe Internet. Thus, via I/O interface 208 base stations 200 may exchangecustomer information and other data as well as synchronize thetransmission of signals to Wts 300 if desired. In addition I/O interface208 provides a high speed connection to the Internet allowing WT 300users to receive and/or transmit information over the Internet via thebase station 300. Receiver 202 processes signals received via receiverantenna 216 and extracts from the received signals the informationcontent included therein. The extracted information, e.g., data andchannel interference report information, is communicated to theprocessor 206 and stored in memory 212 via bus 214. Transmitter 204transmits information, e.g., data, beacon signals, pilot signals,assignment signals, interference report request messages, interferencecontrol indicator signals, to Wts 300 via antenna 218.

As mentioned above, the processor 206 controls the operation of the basestation 200 under direction of routines 220 stored in memory 212.Routines 220 include communications routines 226, and base stationcontrol routines 228. The base station control routines 228 include ascheduler 230, a downlink broadcast signaling module 232, a WT reportprocessing module 234, a report request module 236, and an interferenceindicator module 238. The report request module 236 can generaterequests for specific interference reports concerning a particular BSsector identified in the report request. Generated report requests aretransmitted to one or more wireless terminals when the BS seeksinterference information at a time other than that provided for by apredetermined or fixed reporting schedule. Data/Information 224 includesdownlink broadcast reference signal information 240, wireless terminaldata/information 241, uplink traffic channel information 246,interference report request information messages 248, and interferencecontrol indicator signals 250.

Downlink broadcast reference signal information 240 includes beaconsignal information 252, pilot signal information 254, and assignmentsignal information 256. Beacon signals are relatively high power OFDMbroadcast signals in which the transmitter power is concentrated on oneor a few tones for a short duration, e.g., two symbol times. Beaconsignal information 252 includes identification information 258 and powerlevel information 260. Beacon identification information 258 may includeinformation used to identify and associate the beacon signal withspecific BS 200, e.g., a specific tone or set of tones which comprisethe beacon signal at a specific time in a repetitive downlinktransmission interval or cycle. Beacon power level information 260includes information defining the power level at which the beacon signalis transmitted. Pilot signals may include known signals broadcast to WTsat moderately high power levels, e.g., above ordinary signaling levels,which are typically used for identifying a base station, synchronizingwith a base station, and obtaining a channel estimate. Pilot signalinformation 254 includes identification information 262 and power levelinformation 264. Pilot identification information 262 includesinformation used to identify and associate the pilot signals withspecific base station 200. Pilot power level information 264 includesinformation defining the power level at which the pilot signals aretransmitted. Various signals providing information about signaltransmission power levels, e.g., pilot and beacon signal transmissionpilot levels, may be broadcast for use by wireless terminals indetermining gain ratios and/or interference reports. Assignment signalsincludes broadcast uplink and downlink traffic channel segmentassignment signals transmitted typically at power levels above ordinarysignaling levels so as to reach WTs within its cell which have poorchannel quality conditions. Assignment signaling information 256includes identification information 266 and power level information 268.Assignment signaling identification information 266 includes informationassociating specific tones at specific times in the downlink timingcycle with assignments for the specific BS 200. Assignment power levelinformation 268 includes information defining the power level at whichthe assignment signals are transmitted.

Wireless terminal data/information 241 includes a plurality of sets ofWT data/information, WT 1 information 242, WT N info 244. WT 1information 242 includes data 270, terminal identification information272, interference cost report information 274, requested uplink trafficsegments 276, and assigned uplink traffic segments 278. Data 270includes user data associated with WT 1, e.g., data and informationreceived from WT 1 intended to be communicated by BS 200 either directlyor indirectly to a peer node of WT 1, e.g., WT N, in which WT 1 isparticipating in a communications session. Data 270 also includesreceived data and information originally sourced from a peer node of WT1, e.g., WT N. Terminal identification information 272 includes a BSassigned identifier associating WT 1 to the BS and used by the BS toidentify WT 1. Interference cost report information 274 includesinformation which has been forwarded in a feedback report from WT 1 toBS 200 identifying interference costs of WT 1 transmitting uplinksignaling to the communications system. Requested uplink trafficsegments 276 include requests from WT 1 for uplink traffic segmentswhich are allocated by the BS scheduler 230, e.g., number, type, and/ortime constraint information. Assigned uplink traffic segments 278includes information identifying the uplink traffic segments which havebeen assigned by the scheduler 230 to WT 1.

Uplink traffic channel information 246 includes a plurality of uplinktraffic channel segment information sets including information on thesegments that may be assigned by BS scheduler 230 to WTs requestinguplink air link resources. Uplink traffic channel information 246includes channel segment 1 information 280 and channel segment Ninformation 282. Channel segment 1 information 280 includes typeinformation 284, power level information 286, definition information288, and assignment information 290. Type information 284 includesinformation defining the characteristics of the segment 1, e.g., thefrequency and time extent of the segment. For example, the BS maysupport multiple types of uplink segments, e.g., a segment with a largebandwidth but a short time durations and a segment with a smallbandwidth but a long time duration. Power level information 286 includesinformation defining the specified power level at which the WT is totransmit when using uplink segment 1. Definition information 288includes information defining specific frequencies or tones and specifictimes which constitute uplink traffic channel segment 1. Assignmentinformation 290 includes assignment information associated with uplinktraffic segment 1, e.g., the identifier of the WT being assigned theuplink traffic channel segment 1, a coding and/or a modulation scheme tobe used in uplink traffic channel segment 1.

Interference report request information messages 248, used in someembodiments, are messages to be transmitted, e.g., as a broadcastmessages or as messages directed to specific WTs. The BS 200 maytransmit to Wts 300 on a common control channel instructing the WTs todetermine and report the interference information with respect to aparticular base station transmitter, e.g., base station sectortransmitter, in the communications system. Interference report requestinformation messages 248 normally include base station transmitteridentification information 292 which identifies the particular basestation sector being currently designated for the interference report.As discussed above, some base stations are implemented as single sectorbase stations. Over time BS 200 may change base station identificationinformation 292 to correspond to each of the neighboring transmittersand thereby obtain interference information about multiple neighbors.

Interference control indicator signals 250, used in some embodiments,e.g., where at least some of the uplink traffic segments are notexplicitly assigned by the base station, are signals broadcast by BS 200to Wts 300 to control, in terms of interference, which WTs may useuplink traffic segments. For example, a multi-level variable may be usedwhere each level indicates how tightly the BS 200 would like to controlinterference. Wts 300 which receive this signal can use this signal incombination with their own measured interference to determine whether ornot the WT 300 is allowed to use the uplink traffic segments beingcontrolled.

Communication routines 226 implement the various communicationsprotocols used by the BS 200 and control overall transmission of userdata. Base station control routines 228 control the operation of the I/Odevices 210, I/O interface 208, receiver 202, transmitter 204, andcontrols the operation of the BS 200 to implement the methods of thepresent invention. Scheduler 230 allocates uplink traffic segments underits control to Wts 300 based upon a number of constraints: powerrequirement of the segment, transmit power capacity of the WT, andinterference cost to the system. Thus, the scheduler 230 may, and oftendoes, use information from received interference reports when schedulingdownlink transmissions. Downlink broadcast signaling module 232 uses thedata/information 224 including the downlink broadcast reference signalinformation 240 to generate and transmit broadcast signals such asbeacons, pilot signals, assignments signals, and/or other common controlsignal transmitted at known power levels which may be used by Wts 300 indetermining downlink channel quality and uplink interference levels. WTinterference report processing module 234 uses the data/information 224including the interference cost report information 274 obtained from theWts 300 to process, correlate, and forward uplink interferenceinformation to the scheduler 230. The report request module 236, used insome embodiments, generates a sequence of interference report requestmessages 248 to request a sequence of uplink interference reports, eachreport corresponding to one of its adjacent base stations. Interferenceindicator module 238, used in some embodiments, generates (multi-level)interference control indicator signals 250 which are transmitted to theWts 300 to control access to some uplink traffic channel segments.

FIG. 3 illustrates an exemplary wireless terminal 300, implemented inaccordance with various embodiments. Exemplary wireless terminal 300 maybe a more detailed representation of any of the WTs 106, 108, 118, 120of exemplary system wireless communication system 100 of FIG. 1. WT 300includes a receiver 302, a transmitter 304, I/O devices 310, a processor306, e.g., a CPU, and a memory 312 coupled together via bus 314 overwhich the various elements may interchange data and information.Receiver 302 is coupled to antenna 316; transmitter 304 is coupled toantenna 318.

Downlink signals transmitted from BS 200 are received through antenna316, and processed by receiver 302. Transmitter 304 transmits uplinksignals through antenna 318 to BS 200. Uplink signals includes, e.g.,uplink traffic channel signals and interference cost reports. I/Odevices 310 include user interface devices such as, e.g., microphones,speakers, video cameras, video displays, keyboard, printers, dataterminal displays, etc. I/O devices 310 may be used to interface withthe operator of WT 300, e.g., to allow the operator to enter user data,voice, and/or video directed to a peer node and allow the operator toview user data, voice, and/or video communicated from a peer node, e.g.,another WT 300.

Memory 312 includes routines 320 and data/information 322. Processor 306executes the routines 320 and uses the data/information 322 in memory312 to control the basic operation of the WT 300 and to implementmethods. Routines 320 include communications routine 324 and WT controlroutines 326. WT control routines 326 include a reference signalprocessing module 332, an interference cost module 334, a report formatselection module 329, and a scheduling decision module 330. Referencesignal processing module 332 includes an identification module 336, areceived power measurement module 338, and a channel gain ratiocalculation module 340. Interference cost module 334 includes afiltering module 342, a determination module 344, and a reportgeneration module 346. The report generation module 346 includes aquantization module 348.

Data/information 322 includes downlink broadcast reference signalinformation 349, wireless terminal data/information 352, uplink trafficchannel information 354, received interference report requestinformation message 356, received interference control indicator signal358, and received broadcast reference signals 353.

Downlink broadcast reference signal information 349 includes a pluralityof downlink broadcast reference signal information sets, base station 1downlink broadcast reference signal information 350, base station Mdownlink broadcast reference signal information 351. BS 1 downlinkbroadcast reference signal information includes beacon signalinformation 360, pilot signal information 362, and assignment signalinginformation 364. Beacon signal information 360 includes identificationinformation 366, e.g., BS identifier and sector identifier information,and power level information 368. Pilot signal information 362 includesidentification information 370 and power level information 372.Assignment signaling information 364 includes identification information374 and power level information 376.

Wireless terminal data/information 352 includes data 382, terminalidentification information 384, interference cost report information386, requested uplink traffic segments 388, and assigned uplink trafficsegments 390.

Uplink traffic channel information 354 includes a plurality of uplinktraffic channel information sets, channel 1 information 391, channel Ninformation 392. Channel 1 information 391 includes type information393, power level information 394, definition information 395, andassignment information 396. The scheduling module 330 controls thescheduling of the transmission interference reports, e.g., according toa predetermined schedule, BS requested interference reports in responseto received report requests, and user data.

Received interference report request information message 356 includes abase station identifier 397.

FIG. 4 illustrates an exemplary system 400 implemented in accordancewith various embodiments which will be used to explain various featuresof the invention. The system 400 includes first, second and third cells404, 406, 408 which neighbor each other. The first cell 404 includes afirst base station including a first base station sector transmitter(BSS₀) 410 and a wireless terminal 420 which is connected to BSS₀ 410.The second cell 406 includes a second base station including a secondbase station sector transmitter (BSS₁) 412. The third cell 408 includesa third station base station including a third base station sectortransmitter (BSS₂) 414. As can be seen, signals transmitted between BSS₀and the WT 420 are subjected to a channel gain g₀. Signals transmittedbetween BSS₁ and the WT 420 are subjected to a channel gain g₁. Signalstransmitted between BSS₂ and the WT 420 are subjected to a channel gaing₂.

Assume that the WT 420 is connected to BSS₀ 410 using BSS₀ 410 as itsattachment point. A gain ratio G_(i)=ratio of the channel gain from theBSSi to the WT 420 to the channel gain from the BSS₀ to the WT 420. Thatis:G _(i) =g _(i) /g ₀

Assuming that beacon signals are transmitted from the first, second andthird BSSs at the same power level, the received power (PB) of thebeacon signals received from the base stations BSS₀, BSS₁, BSS₂ can beused to determine the gain ratio's as follows:G ₀ =g ₀ /g ₀=1=PB ₀ /PB ₀G ₁ =g ₁ /g ₀ =PB ₁ /PB ₀G ₂ =g ₂ /g ₀ PB ₂ /PB ₀

The following discussion will focus on the operation of the uplinktraffic channel in accordance with various embodiments. In the exemplarysystem, the traffic segments that constitute the uplink traffic channelmay be defined over different frequency and time extents in order tosuit a broad class of wireless terminals that are operating over adiverse set of wireless channels and with different device constraints.FIG. 6 is a graph 100A of frequency on the vertical axis 102A vs time onthe horizontal axis 104A. FIG. 6 illustrates two kinds of trafficsegments in the uplink traffic channel. Traffic segment denoted A 106Aoccupies twice the frequency extent of the traffic segment denoted B108A. The traffic segments in the uplink traffic channel can be shareddynamically among the wireless terminals that are communicating with thebase station. A scheduling module that is part of the base station canrapidly assign the traffic channel segments to different users accordingto their traffic needs, device constraints and channel conditions, whichmay be time varying in general. The uplink traffic channel is thuseffectively shared and dynamically allocated among different users on asegment-by-segment basis. The dynamic allocation of traffic segments isillustrated in FIG. 6 in which segment A is assigned to user #1 by thebase station scheduler and segment B is assigned to user #2.

In the exemplary system, the assignment information of traffic channelsegments is transported in the assignment channel, which includes aseries of assignment segments. Each traffic segment is associated with acorresponding unique assignment segment that conveys the assignmentinformation that may include the identifier of the wireless terminal andalso the coding and modulation scheme to be used in that trafficsegment. FIG. 7 is a graph 200A of frequency on the vertical axis 202Avs. time on the horizontal axis 204A. FIG. 7 shows two assignmentsegments, A′ 206A and B′ 208A, which convey the assignment informationof the uplink traffic segments A 210A and B 212A, respectively. Theassignment channel is a shared channel resource. The wireless terminalsreceive the assignment information conveyed in the assignment channeland then transmit on the uplink traffic channel segments according tothe assignment information.

The base station scheduler 230 allocates traffic segments based on anumber of considerations. One constraint is that the transmit powerrequirement of the traffic channel should not exceed the transmit powercapability of the wireless terminal. Hence, wireless terminals that areoperating over weaker uplink channels may be allocated traffic segmentsthat occupy a narrower frequency extent in the exemplary system in orderthat the instantaneous power requirements are not severely constraining.Similarly, wireless terminals that generate a greater amount ofinterference may also be allocated traffic segments that include asmaller frequency extent in order to reduce the impact of theinstantaneous interference generated by them. The total interference iscontrolled by scheduling the transmission of the wireless terminals onthe basis of their interference costs to the system, which are definedin the following.

The wireless terminals determine their interference costs to the systemfrom the received downlink broadcast signals. In one embodiment, thewireless terminals report their interference costs to the base station,in the form of interference reports, which then makes uplink schedulingdecisions to control uplink interference. In another embodiment, thebase station broadcasts an interference control indicator, and thewireless terminals compare their interference costs with the receivedindicator to determine their uplink transmission resources in anappropriate manner, e.g., mobiles have uplink transmission costs below alevel indicated by the control indicator may transmit while mobiles withinterference costs exceeding the cost level indicated by the controlindicator will refrain from transmitting.

Exemplary Interference costs which may be considered will now bedescribed.

Consider a wireless terminal labeled m₀. Assume the wireless terminal isconnected to base station B₀. Denote G_(0,k) the channel gain betweenthis wireless terminal and base station B_(k), for k=0, 1, . . . , N−1,where N is the total number of base stations in the system.

In the exemplary system, the amount of power transmitted by wirelessterminal m₀ on the uplink traffic segment is usually a function of thecondition of the wireless channel from wireless terminal m₀ to the basestation B₀, the frequency extent, and the choice of code rate on thetraffic segment. The frequency extent of the segment and the choice ofcode rate determine the transmit power used by the mobile, which is thequantity that directly causes interference. Assume that the SNR requiredfor the base station receiver to decode the traffic segment necessitatesa receive power P_(R) per tone of the traffic segment (which is afunction of the choice of code rate and the channel conditions overwhich the mobile terminal is operating). This is related to the transmitpower per tone of the wireless terminal, P_(T), as follows:P_(R)=P_(T)G_(0,0)

The interference per tone produced by this wireless terminal atneighboring base station k can then be computed as follows:

$P_{I,k} = {{P_{T}G_{0,k}} = {P_{R}\frac{G_{0,k}}{G_{0,0}}}}$Denote

$r_{0,k} = {\frac{G_{0,k}}{G_{0,0}}.}$From this expression, it is clear that the interference generated bywireless terminal m₀ at base station B_(k) is proportional to itstransmit power as well as the ratio of the channel gains to base stationk and to its own base station. Hence, r_(0,k) is called the interferencecost of wireless terminal m₀ to base station B_(k).

Generalizing this concept, the total interference per tone produced by awireless terminal to all the neighboring base stations is

$P_{I}^{total} = {{P_{T}\left( {G_{0,1} + G_{0,2} + \ldots + G_{0,N}} \right)} = {{P_{R}\frac{\sum\limits_{k \neq 0}^{N}\; G_{0,k}}{G_{{0,0}\;}}} = {P_{R}{\sum\limits_{k = 1}^{N}\; r_{0,k}}}}}$Therefore, {r_(0,1), . . . , r_(0,N)} are the interference costs ofwireless terminal m₀ to the entire system.

It is useful to note that the aggregate instantaneous interferenceproduced by the mobile m₀ to base station B_(k) is actually given byn_(tones)r_(0,k) where n_(tones) is the frequency extent of the trafficsegment.

Method of determining interference costs in some embodiments will now bedescribed. In one exemplary embodiment, each base station 102, 114 inthe exemplary system 100 broadcasts periodic reference signals at highpower that the wireless terminals can detect and decode. The referencesignals include beacons, pilots, or other common control signals. Thereference signals may have a unique pattern that serves to identify thecell and the sector of the base station.

In the exemplary OFDM system 100, a beacon or pilot signal can be usedas the reference signals. A beacon signal is a special OFDM symbol inwhich most of the transmission power is concentrated on a small numberof tones. The frequency location of those high-power tones indicates theidentifier of the base station. A pilot signal can have a specialhopping pattern, which also uniquely specifies the identifier of thebase station 102. Thus, a base station sector can be identified in theexemplary system from beacon and/or pilot signals.

In a CDMA system, a pilot signal can be used as the reference signal. Inthe IS-95 system, for example, a pilot is a known spreading sequencewith a particular time offset as the identifier of the base station.

While the exemplary system 100 described above uses beacon or pilotsignals to provide a reference signal for path loss estimation, theinvention is applicable in a wide variety of systems that may use othertechniques to provide reference signals.

The reference signals are transmitted at known powers. Differentreference signals may be transmitted at different powers. Different basestations 102, 114 may use different power levels for the same type ofreference signals as long as these powers are known to the mobileterminals.

The wireless terminal 106 first receives the reference signals to getthe identifier of the base station 102. Then, the wireless terminal 106measures the received power of the reference signals, and calculates thechannel gain from the base station 102 to the wireless terminal 106.Note that at a given location, the wireless terminal may be able toreceive the reference signals from multiple base stations 102, 114. Onthe other hand, the wireless terminal may not be able to receive thereference signals from all the base stations in the entire system. Inthe exemplary system, wireless terminal m₀ monitors G_(0,0) for itsconnected base station B₀, and G_(0,k) for base station B_(k) if it canreceive the corresponding reference signal. Therefore, wireless terminalm₀ maintains an array of interference costs {r_(0,k)} for the set ofbase stations whose reference signals it can receive.

Note that the wireless terminal 106 can derive the interference costs bycombining the estimation from multiple reference signals. For example,in the exemplary OFDM system 100, the wireless terminal 106 may use bothbeacons and pilots to arrive at the estimation of {r_(0,k)}.

The information of interference costs {r_(0,k)} is to be used to controlthe uplink interference and increase overall system capacity. The uplinktraffic channels can be used in two modes and the following describesthe use of interference costs in both modes.

It should be pointed out that the wireless terminals 106, 108 measuredthe channel gain information from the downlink reference signals, whilethe interference are a measure of the costs the interference will havein terms of impact on the uplink. The channel gains of the downlink andthe uplink between a wireless terminal 106 and a base station 102 maynot be same at all times. To remove the effect of short-term variations,the estimates of the channel gains from the downlink reference signalsmay, and in some embodiments are, averaged (using a form of lowpassfiltering for example) to obtain the estimates of interference costs{r_(0,k)}.

Use of determined Interference Costs in a Scheduled Mode of operationwill now be discussed. In one particular exemplary mode of operation,each of the uplink traffic segments are explicitly assigned by the basestation so that one uplink traffic segment is only used by at most onewireless terminal. In the exemplary OFDM system, as the traffic segmentsare orthogonal with each other, there is normally no intracellinterference in an uplink traffic segment in this mode.

To facilitate scheduling at the base station 102, in accordance with theinvention, each wireless terminal 106, 108 sends to the base station162, which the wireless terminal is connected to, a sequence ofinterference reports. The reports, in some embodiments are indicative ofthe calculated interference costs {r_(0,k)}. In an extreme case, areport is a control message that includes the entire array ofinterference costs {r_(0,k)}. To reduce the signaling overhead, however,in an embodiment only a quantized version of the array {r_(0,k)} istransmitted. There are a number of ways to quantize {r_(0,k)}, as listedbelow.

-   -   Report r_(0,total), which is the sum of all {r_(0,k)}.    -   Report the maximum of {r_(0,k)} and the index k associated with        the maximum.    -   Report {r_(0,k)} one-by-one, and the associated index k,        periodically.    -   Use a small number of levels to report r_(0,k). For example, two        levels to indicate whether r_(0,k) is strong or weak.

After receiving the one or more interference reports, the base stationschedules, e.g., assigns, the traffic segments as a function of theinterference information. One scheduling policy is to restrict the totalinterference produced by all scheduled wireless terminals to apre-determined threshold. Another scheduling policy is categorize thewireless terminals according to their reported {r_(0,k)} to severalgroups such that the group with large interference costs is preferablyassigned traffic segments that include a smaller frequency extent inorder to reduce the impact of the instantaneous interference generated.

Consider one embodiment in which each base station 102 is aware of itsneighbor set, i.e., the set of base stations 114, etc. that aredetermined to be neighbors from the perspective of interference. In abasic embodiment, the base station 102 just attempts to control thetotal interference to the neighboring base stations. The basicembodiment may be coarse in the sense that almost all the interferencemay be directed to a particular one of the neighboring base stations(cell X), e.g., because all the scheduled wireless terminals may beclose to cell X. In this case, cell X experiences severe interference atthis time instant. At another time instant, the interference may beconcentrated on a different neighboring base station, in which case cellX experiences little interference. Hence, in the above embodiment oftotal interference control, the interference to a particular neighboringbase station may have large variation. In order to avoid destabilizingthe intercell interference, the base station 102 may have to leavesufficient margin in the total generated interference to compensate thelarge variation.

In an enhanced embodiment, the base station 102 broadcasts a message ona common control channel instructing the wireless terminals 106, 108 todetermine and report the interference cost with respect to a particularbase station B_(k). Thus, the wireless terminals, m_(j), j=0, 1, 2, . .. will send the reports of r_(j,k). Over time, the base station 102repeats this process for each member of its neighbor set and determinesthe set of wireless terminals 106, 108 that interfere with each of thebase stations. Once this categorization is complete, the base station102 can simultaneously allocate uplink traffic segments to a subset ofwireless terminals 106, 108 that interfere with different base stations,thereby reducing the variation of the interference directed to anyparticular base station. Advantageously, because the interference hasless variation, the base station 102 may allow greater totalinterference to be generated without severely impacting the systemstability, thus increasing the system capacity. Wireless terminals 106,108 in the interior of the cell 104 cause negligible interference toneighboring base stations 114 and therefore may be scheduled at anytime.

Use of Interference Costs in a Non-scheduled Mode of operation used insome but not necessarily all implementations will now be discussed.

In this non-scheduled mode, each of the uplink traffic segments are notexplicitly assigned by the base station 102. As a result, one uplinktraffic segment may be used by multiple wireless terminals 106, 108. Ina CDMA system, as the uplink traffic segments are not orthogonal witheach other, there is generally intracell interference in an uplinktraffic segment in this mode.

In this mode, each wireless terminal 106, 108 makes its own schedulingdecision of whether it is to use an uplink traffic segment and if so atwhat data rate and power. To help reduce excessive interference andmaintain system stability, in accordance with various embodiments, thebase station broadcasts the interference control indicator. Eachwireless terminal 106, 108 compares the reference levels with itsinterference costs and determines its scheduling decision.

In one embodiment, the interference control indicator can be amulti-level variable and each level is to indicate how tightly the basestation 102 would like to control the total interference. For example,when the lowest level is broadcasted, then each of the wirelessterminals 106, 108 are allowed to use each of the traffic channelsegments at each of the rates. When the highest level is broadcasted,then only the wireless terminals 106, 108 whose interference costs arevery low can use the traffic channel segments. When a medium level isbroadcasted, then the wireless terminals 106, 108 whose interferencecosts are low can use all the traffic channel segments, preferably thetraffic segments that include a larger frequency extent, while thewireless terminals 106, 108 whose interference costs are high can onlyuse the traffic segments that consist of a smaller frequency extent andat lower data rate. The base station 102 can dynamically change thebroadcasted interference control level to control the amount ofinterference the wireless terminals 106, 108 of the cell 104 generate toother base stations.

FIG. 5, comprising the combination of FIG. 5A, FIG. 5B, and FIG. 5C is aflowchart 1000 of an exemplary method of operating a wireless terminal,e.g., mobile node, in accordance with various embodiments. Operationstarts in step 1002, where the wireless terminal is powered on andinitialized. Operation proceeds from step 1002 to step 1004, step 1006and, via connecting node B 1005 to step 1008.

In step 1004, the wireless terminal is operated to receive beacon andpilot signals from the current base station sector connection. Operationproceeds from step 1004 to step 1010. In step 1010, the wirelessterminal measures the power of the received beacon signal (PB₀) andreceived pilot channel signals (PP₀) for the current base station sectorconnection. Operation proceeds from step 1010 to step 1012. In step1012, the wireless terminal derives current connection base stationsector transmitter information, e.g., a BSS_slope and a BSS_sector typefrom the received beacon signal. Step 1012 includes sub-step 1013. Insub-step 1013, the wireless terminal determines a power transmissiontier level associated with the current connection base station sectorand tone block being used.

In step 1006, the wireless terminal receives beacon signal from one ormore interfering base station sectors 1006. Operation proceeds from step1006 to step 1014. Subsequent operations 1014, 1016, 1018 are performedfor each interfering base station sector, e.g., interfering base stationsector _(i) (BSS_(i)).

In step 1014, the wireless terminal measures the power of receivedbeacon signal (PB_(i)) for the interfering base station sector.Operation proceeds from step 1014 to step 1016. In step 1016, thewireless terminal derives interfering base station sector transmitterinformation, e.g., a BSS_slope and a BSS_sector type from the receivedbeacon signal. Step 1016 includes sub-step 1017. In sub-step 1017, thewireless terminal determines a power transmission tier level associatedwith an interfering base station sector and tone block being used.

Operation proceeds from steps 1012 and step 1016 to step 1018. In step1018 the wireless terminal computes a channel gain ratio using themethod of sub-step 1020 or the method of sub-step 1022.

In sub-step 1020, the wireless terminal uses beacon signal informationto compute the channel gain ratio, G_(i). Sub-step 1020 includessub-step 1024, where the wireless terminal computes G_(i)=PB_(i)/PB₀.

In sub-step 1022, the wireless terminal uses beacon signal informationand pilot signal information to compute the channel gain ratio G_(i).Sub-step 1022 includes sub-step 1026, where the wireless terminalcomputes G_(i)=PB_(i)/(PP₀* K * Z₀), where K=per tone transmitter powerbeacon reference level for a tier 0 tone block/per tone transmitterpilot signal reference level for a tier 0 tone block, and Z₀=power scalefactor associated with the power transmission tier level of the toneblock for the current base station sector connection transmitter toneblock.

Operation proceeds from step 1018 via connecting node A 1042 to step1043, where the wireless terminal generates one or more interferencereports.

Returning to step 1008, in step 1008 the wireless terminal is operatedto receive broadcast load factor information. Thus, in the exemplaryembodiment, the wireless terminal receives the load factor informationof the current serving base station sector from the broadcastinformation sent by the current serving base station sector transmitter.The wireless terminal may receive the load factor information of theinterfering serving base station sector from the broadcast informationsent by the current or the interfering serving base station sectortransmitter. While load factor information is shown as being receivedfrom the current serving base station sector, alternatively, load factorinformation can be received from other nodes and/or pre-stored in thewireless terminal. For each base station sector under consideration,operation proceeds to step 1028. In step 1028 the wireless terminaldetermines whether or not the load factor was successfully recoveredfrom the received signal. If the load factor was successfully recoveredfrom the received signal operation proceeds to step 1030, where thewireless terminal stores the load factor. For example load factor b₀=theload factor for the current serving base station sector, and load factorb_(k)=the load factor for interfering base station section k. If theload factor was not successfully recovered from the received signal,then operation proceeds to step 1032, where the wireless terminal setsthe load factor to 1. Load factors (b₀ 1032, b₁ 1034, . . . , b_(k)1038, . . . bn 1040) are obtained, with each load factor being sourcedfrom one of steps 1030 and step 1032.

Returning to step 1043, in step 1043 the wireless terminal generates oneor more interference reports. Step 1043 includes sub-step 1044 andsub-step 1048. In sub-step 1044, the wireless terminal generates aspecific type report conveying interference by a specific interferingbase station sector to the serving base station sector. Step 1044includes sub-step 1046. In sub-step 1046, the wireless terminal computesthe report value=(b₀/Z₀)/(G_(k)* b_(k)/Z_(k)), where b₀ is the loadingfactor of the current serving BSS and b_(k) is the loading factor if aninterfering BSS to which the report corresponds, G_(k)=G_(i) for i=k,and Z₀ is the power scale factor associated with the power transmissiontier level of the tone block for the current BSS connection transmittertone block, and Z_(k) is the power scale factor associated with thepower transmission tier level of the tone block for the interfering basestation sector to which the report corresponds.

In sub-step 1048, the wireless terminal generates a generic type reportconveying information of interference by one or more interfering BSSs tothe serving BSS, e.g., using information from each of the measuredbeacon signals of interfering base station sectors including using loadfactor information and power scale factor information.

In some embodiments, step 1043 includes quantization.

Operation proceeds from step 1043 to step 1050 where the wirelessterminal is operated to transmit the report to the current serving basestation sector serving as the current attachment point for the wirelessterminal. In some embodiments, the transmission of a report is inresponse to a request from the serving base station sector. In someembodiments, the type of report transmitted, e.g., specific or generic,is in response to received signaling from a base station sectoridentifying the type of report. In some embodiments, the transmission ofa particular specific type report reporting on interference associatedwith a particular base station sector is in response to a received basestation signal identifying the particular base station sector. Invarious embodiments, interference reports are transmitted periodicallyin accordance with a reporting schedule being followed by the wirelessterminal, e.g., as part of dedicated control channel structure. In somesuch embodiments, for at least some of the interference reportstransmitted, the base station does not signal any report selectioninformation to select the report.

In some embodiments, the system includes a plurality of powertransmission tier levels, e.g., three, with a different power scalefactor associated with each tier level. For example, in one exemplaryembodiment a power scale factor of 0 dB is associated with a tier level0 tone block, while a power scale factor of 6 dB is associated with atier 1 level tone block, and a power scale factor of 12 dB is associatedwith a tier 2 tone block. In some embodiments, each attachment pointcorresponds to a base station sector transmitter and a tone block, andeach attachment point BSS transmitter tone block may be associated witha power transmission tier level. In some embodiments there are aplurality of downlink tones blocks, e.g., three tone block (tone block0, tone block 1, tone block 2) each having 113 contiguous evenly spacedtones. In some embodiments, the same tone block, e.g., tone block 0,used different base station sector transmitters, has a different powertransmission tier level associated with the different base stationsector transmitters. A wireless terminal, identifying a particularattachment point, corresponding to a base station sector transmitter andtone block, e.g., from information conveyed via its beacon signal usingtone location and/or time position with a recurring transmissionpattern, can use stored information to associate the identifiedattachment point with a particular power transmission tier level andpower scale factor for a particular tone block.

In some embodiments, the loading factor, e.g., b_(k), is a value greaterthan or equal to 0 and less than or equal to one. In some embodiments,the value is communicated from a base station sector to a wirelessterminal represents one of a plurality of levels, e.g., 0 dB, −1 dB, −2dB, −3 dB, −4 dB, −6 dB, −9 dB, -infinity dB.

In some embodiments, the beacon signals are transmitted at the samepower from a base station sector transmitter irrespective of powertransmission tier associated with the tone block being used; however,other downlink signals, e.g., pilot signals, are affected by the powertransmission tier associated with the tone block for the base stationsector transmitter. In some embodiments, the parameter K is at valuegreater than or equal to 6 dB. For example in one exemplary embodimentthe parameter K=23.8 dB −7.2 dB=16.6 dB.

FIG. 8 shows an exemplary communication system 800 implemented inaccordance with various embodiments. Exemplary communications system 800includes multiple cells: cell 1 802, cell M 804. Exemplary system 800is, e.g., an exemplary orthogonal frequency division multiplexing (OFDM)spread spectrum wireless communications system such as a multiple accessOFDM system. Each cell 802, 804 of exemplary system 800 includes threesectors. Cells which have not be subdivided into multiple sectors (N=1),cells with two sectors (N=2) and cells with more than 3 sectors (N>3)are also possible in accordance with various embodiments. Each sectorsupports one or more carriers and/or downlink tones blocks. In someembodiments, each downlink tone block has a corresponding uplink toneblock. In some embodiments at least some of the sectors support threedownlink tones blocks. Cell 802 includes a first sector, sector 1 810, asecond sector, sector 2 812, and a third sector, sector 3 814.Similarly, cell M 804 includes a first sector, sector 1 822, a secondsector, sector 2 824, and a third sector, sector 3 826. Cell 1 802includes a base station (BS), base station 1 806, and a plurality ofwireless terminals (WTs) in each sector 810, 812, 814. Sector 1 810includes WT(1) 836 and WT(N) 838 coupled to BS 806 via wireless links840, 842, respectively; sector 2 812 includes WT(1′) 844 and WT(N′) 846coupled to BS 806 via wireless links 848, 850, respectively; sector 3814 includes WT(1″) 852 and WT(N″) 854 coupled to BS 806 via wirelesslinks 856, 858, respectively. Similarly, cell M 804 includes basestation M 808, and a plurality of wireless terminals (WTs) in eachsector 822, 824, 826. Sector 1 822 includes WT(1″″) 868 and WT(N″″) 870coupled to BS M 808 via wireless links 880, 882, respectively; sector 2824 includes WT(1′″″) 872l and WT(N′″″) 874 coupled to BS M 808 viawireless links 884, 886, respectively; sector 3 826 includes WT(1″″″)876 and WT(N″″″) 878 coupled to BS M 808 via wireless links 888, 890,respectively.

System 800 also includes a network node 860 which is coupled to BS1 806and BS M 808 via network links 862, 864, respectively. Network node 860is also coupled to other network nodes, e.g., other base stations, AAAserver nodes, intermediate nodes, routers, etc. and the Internet vianetwork link 866. Network links 862, 864, 866 may be, e.g., fiber opticcables. Each wireless, e.g. WT 1 836, includes a transmitter as well asa receiver. At least some of the wireless terminals, e.g., WT(1) 836,are mobile nodes which may move through system 800 and may communicatevia wireless links with the base station in the cell in which the WT iscurrently located, e.g., using a base station sector attachment point.The wireless terminals, (WTs), e.g. WT(1) 836, may communicate with peernodes, e.g., other WTs in system 800 or outside system 800 via a basestation, e.g. BS 806, and/or network node 860. WTs, e.g., WT(1) 836 maybe mobile communications devices such as cell phones, personal dataassistants with wireless modems, laptop computers with wireless modems,data terminals with wireless modems, etc.

An exemplary 4 bit downlink beacon ratio report (DLBNR4) will now bedescribed. The beacon ratio report provides information which is afunction of received measured downlink broadcast signals, e.g., beaconsignals and/or pilot signals, from a serving base station sector andfrom one or more other interfering base station sectors. Qualitatively,the beacon ratio report can be used to estimate the relative proximityof the WT to other base station sectors. The beacon ratio report can be,and in some embodiments is, used at the serving BS sector in controllingthe uplink rate of the WT to prevent excessive interference to othersectors. The beacon ratio report, in some embodiments, is based on twofactors: (i) estimated channel gain ratios, denoted G_(i), and (ii)loading factors, denoted b_(i).

The channel gain ratios are defined, in some embodiments, as follows. Inthe tone block of the current connection, the WT, in some embodiments,determines an estimate of the ratio of the uplink channel gain from theWT to any interfering Base station sector i (BSS i) to the channel gainfrom the WT to the serving BSS. This ratio is denoted as G_(i).Typically, the uplink channel gain ratio is not directly measurable atthe WT. However, since the uplink and downlink path gains are typicallysymmetric, the ratio can be estimated by comparing the relative receivedpower of downlink signals from the serving and interfering BSSs. Onepossible choice for the reference downlink signal is the downlink beaconsignal, which is well-suited for this purpose since it can be detectedin very low SNR. In some embodiments, beacon signals have a higher pertone transmission power level than other downlink signals from a basestation sector. Additionally, the characteristics of the beacon signalare such that precise timing synchronization is not necessary to detectand measure the beacon signal. For example, the beacon signal is, insome embodiments, a high power narrowband, e.g., single tone, two OFDMsymbol transmission time period wide signal. Thus at certain locations,a WT is able to detect and measure a beacon signal from a base stationsector, where the detection and/or measurement of other downlinkbroadcast signals, e.g., pilot signals may not be feasible. Using thebeacon signal, the uplink path ratio would be given by G_(i)=PB_(i)/PB₀,where PB_(i) and PB₀ are, respectively, the measured received beaconpower from the interfering and serving base station sectors,respectively.

Since the beacon is typically transmitted rather infrequently, the powermeasurement of the beacon signal may not provide a very accuraterepresentation of average channel gain, especially in a fadingenvironment where the power changes rapidly. For example, in someembodiments one beacon signal, which occupies 2 successive OFDM symboltransmission time periods in duration and which corresponds to adownlink tone block of a base station sector, is transmitted for everybeaconslot of 912 OFDM symbol transmission time periods.

Pilot signals, on the other hand, are often transmitted much morefrequently than beacon signals, e.g., in some embodiments pilot signalsare transmitted during 896 out of the 912 OFDM symbol transmission timeperiods of a beaconslot. If the WT can detect the pilot signal from theBS sector, it can estimate the received beacon signal strength from themeasured received pilot signal instead of using a beacon signalmeasurement. For example, if the WT can measure the received pilotpower, PP_(i), of the interfering BS sector, then it can estimate thereceived beacon power PB_(i) from estimated PB_(i)=KZ_(i)PP_(i), where Kis a nominal ratio of the beacon to pilot power of the interferingsector that is the same for each of the BS sectors, and Z_(i) is ascaling factor that is sector dependent.

Similarly, if the pilot signal power from the serving BS is measurableat the WT, then the received beacon power PB₀ can be estimated from therelation, estimated PB₀=KZ₀PP₀, where Z₀ and PP₀ are, respectively, thescaling factor and measured received pilot power from the serving basestation sector.

Observe that if the received pilot signal strength is measurablecorresponding to the serving base station sector, and the receivedbeacon signal strength is measurable corresponding to interfering basestation sector, the beacon ratio can be estimated from:G _(i) =PB _(i)/(PP ₀ K Z ₀).

Observe that if the pilot strengths are measurable in both the servingand interfering sectors, the beacon ratio can be estimated from:G _(i) =PP _(i) K Z _(i)/(PP ₀ K Z ₀)=PP _(i) Z _(i)/(PP ₀ Z ₀).The scaling factors K, Z_(i) and Z₀ are either system constants, or canbe inferred by the WT, from other information from the BS. In someembodiments, some of the scaling factors (K, Z_(i), Z₀A) are systemconstants and some of the scaling factors (K, Z_(i), Z₀) are inferred bythe WT, from other information form the BS.

In some multicarrier systems with different power levels on differentcarriers, the scaling factors, Z_(i) and Z₀, are a function of thedownlink tone block. For example, an exemplary BSS has three power tierlevels, and one of the three power tier levels is associated with eachdownlink tone block corresponding to a BSS attachment point. In somesuch embodiments, a different one of the three power tier levels isassociated with each of the different tone blocks of the BSS. Continuingwith the example, for the given BSS, each power tier level is associatedwith a nominal bss power level (e.g., one of bssPowerNominal0,bssPowerNominal1, and bssPowerNominal2) and the pilot channel signal istransmitted at a relative power level with respect to a nominal bsspower level for the tone block, e.g., 7.2 dB above the nominal bss powerlevel being used by the tone block; however, the beacon per tonerelative transmission power level for the BSS is the same irrespectiveof the tone block from which the beacon is transmitted, e.g., 23.8 dBabove the bss power level used by the power tier 0 block(bssPowerNominal0). Consequently, in this example for a given BSS, thebeacon transmit power would be the same in each of the tone blocks,while the pilot transmit power is different, e.g. with the pilottransmit power of different tone blocks corresponding to different powertier levels. One set of scale factors for this example would be,K=23.8−7.2 dB, which is the ratio of the beacon to pilot power for tier0, and Z_(i) is set to the relative nominal power of the tier of theinterfering sector to the power of a tier 0 sector.

In some embodiments, the parameter Z₀ is determined from storedinformation, e.g., Table 900 of FIG. 9, according to how the tone blockof the current connection is used in the serving BSS as determined bythe bssSectorType of the serving BSS. For example, if the tone block ofthe current connection is used as a tier 0 tone block by the servingBSS, the Z₀=1; if the tone block of the current connection is used as atier 1 tone block by the serving BSS, the Z₀=bssPowerBackoff01; if thetone block of the current connection is used as a tier 2 tone block bythe serving BSS, the Z₀=bssPowerBackoff02.

FIG. 9 includes exemplary power scaling factor table 900. First column902 lists the use of the tone block as either a tier 0 tone block, tier1 tone block, or tier 2 tone block. Second column 904 lists the scalingfactor associated with each tier (0,1,2) tone block, as (1,bssPowerBackoff01, bssPowerBackoff02), respectively. In someembodiments, bssPowerBackoff01 is 6 dBs while bssPowerBackoff02 is 12dB.

In some embodiments, the DCCH DLBNR4 report can be one of a genericbeacon ratio report and a special beacon ratio report. In some suchembodiments, a downlink traffic control channel, e.g., a DL.TCCH.FLASHchannel, sends a special frame in a beaconslot, the special frameincluding a “Request for DLBNR4 report field”. That field can be used bythe serving BSS to control the selection. For example, if the field isset to zero then, the WT reports a generic beacon ratio report;otherwise the WT reports the special beacon ratio report.

A generic beacon ratio report, in accordance with various embodiments,measures the relative interference cost the WT would generate to all theinterfering beacons or the “closest” interfering beacon, if the WT wereto transmit to the serving BSS in the current connection. A specialbeacon ratio report, in accordance with some embodiments measures therelative interference cost the WT would generate to a specific BSS, ifthe WT were to transmit to the serving BSS in the current connection.The specific BSS is the one indicated using information received in theRequest for DLBNR4 field of the special downlink frame. For example, insome embodiments, the specific BSS is the one whose bssSlope is equal tothe value of the “Request for DLBNR4 report field”, e.g., in unsignedinteger format, and whose bssSectorType is equal tomod(ulUltraslotBeaconslotIndex,3), where ulUltraslotBeaconslotIndex isthe uplink index of the beaconslot within the ultraslot of the currentconnection. In some exemplary embodiments, there are 18 indexedbeaconslots within an ultraslot.

In various embodiments, both the generic and the special beacon ratiosare determined from the calculated channel gain ratios G1, G2, . . . ,as follows. The WT receives an uplink loading factor sent in a downlinkbroadcast system subchannel and determines a variable b₀ from uplinkloading factor table 950 of FIG. 10. Table 950 includes a first column952 listing eight different values that may be used for the uplinkloading factor (0, 1, 2, 3, 4, 5, 6, 7); second column 954 lists thecorresponding values for the b value in dB (0, −1, −2, −3, −4, −6,−9−infinity), respectively. For other BSSi, the WT attempts to receiveb_(i) from the uplink loading factor sent in the downlink broadcastsystem subchannel of the BSS i in the tone block of the currentconnection. If the WT is unable to receive the UL loading factor b_(i),the WT sets b_(i)=1.

In some embodiments, in the single carrier operation, the WT calculatesthe following power ratio as the generic beacon ratio report:b₀/(G₁b₁+G₂b₂+ . . . ) when ulUltraslotBeaconslot Index is even orb₀/max(G₁b₁, G₂b₂, . . . ) when ulUltraslotBeaconslotIndex is odd, whereulUltraslotBeaconslotIndex is the uplink index of the beaconslot withinthe ultraslot of the current connection and the operation+represents aregular addition. When required to send a specific beacon ratio report,the WT, in some embodiments, calculates b₀/(G_(k)B_(k)), where index krepresents the specific BSS k. In some embodiments, there are 18 indexedbeaconslots within an ultraslot.

FIG. 11 is a table 1100 illustrating an exemplary format for a 4 bitdownlink beacon ratio report (DLBNR4), in accordance with variousembodiments. First column 1102 lists the 16 various bit patterns thatthe report can convey, while second column 1104 lists the reported powerratio reported corresponding to each bit pattern, e.g., ranging from −3dB to 26 dBs. The wireless terminal reports the generic and specificbeacon ratio reports by selecting and communicating the DLBNR4 tableentry that is closed to the determined report value. Although in thisexemplary embodiment, the generic and specific beacon ratio reports usethe same table for DLBNR4, in some embodiments, different tables may beused.

FIG. 12 is a drawing of an exemplary orthogonal frequency divisionmultiplexing (OFDM) wireless communications system 8000, e.g., an OFDMspread spectrum multiple access wireless communications system,implemented in accordance with various embodiments. Exemplary wirelesscommunications system 800 includes a plurality of base stations coupledtogether via a backhaul network and a plurality of wireless terminals,e.g., mobile nodes. Exemplary base stations (base station 1 8002, basestation 2 8004, base station 3 8006, base station 4 8008) and exemplarywireless terminal 1 (WT1) 8010 are shown in FIG. 12.

Base station 1 8002 is a three sector base station including a basestation sector SO (BSS 0) 8012, a base station sector S1 (BSS 1) 8014,and a base station sector S2 (BSS 2) 8016. Each base station sector(8012, 8014, 8016) has a corresponding nominal tier 0 power level (BSS 0nominal tier 0 power level 8018, BSS 1 nominal tier 0 power level 8020,BSS 2 nominal tier 0 power level 8022). Base station 2 8004 is a threesector base station including a base station sector S0 (BSS 0) 8024, abase station sector S1 (BSS 1) 8026, and a base station sector S2 (BSS2)8028. Each base station sector (8024, 8026, 8028) has a correspondingnominal tier 0 power level (BSS 0 nominal tier 0 power level 8030, BSS 1nominal tier 0 power level 8032, BSS 2 nominal tier 0 power level 8034).Base station 3 8006 is a three sector base station including a basestation sector S0 (BSS 0) 8036, a base station sector SI (BSS 1) 8038,and a base station sector S2 (BSS2) 8040. Each base station sector(8036, 8038, 8040) has a corresponding nominal tier 0 power level (BSS 0nominal tier 0 power level 8042, BSS 1 nominal tier 0 power level 8044,BSS 2 nominal tier 0 power level 8046). Base station 4 8008 is a singlesector base station which has a nominal tier 0 power level 8048.

Each nominal tier 0 power level corresponds to a power level associatedwith one of the downlink tones blocks being used by the correspondingbase station sector transmitter. In some embodiments, each downlink toneblock is associated with a corresponding uplink tone block. In thisexemplary embodiment each base station sector corresponds to one or morephysical attachment points, each physical attachment point correspondingto a downlink/uplink tone block pair. For a base station sectortransmitter which uses multiple downlink tone blocks, e.g.,corresponding to multiple physical attachment points, to communicatedownlink user data, the nominal tier 0 power level is associated withthe downlink tone block having the highest power level. In addition, theother downlink tone blocks, are referenced in nominal power level withrespect to the tier 0 tone block power level, with the nominal powerlevels of those tone blocks having a lower value. For example, for agiven BSS, a tier 1 tone block has a lower power level than a tier 0tone block, and a tier 2 tone block has a lower power level than a tier1 tone block.

FIG. 13 illustrates the exemplary system 8000 of FIG. 12, and providesadditional detail corresponding to each of the base station sectors toillustrate various features. This exemplary embodiment represents awireless communications system using three non-overlapping downlink toneblocks (tone block 0, tone block 1, and tone block 2). For example, eachdownlink tone block, in some embodiments, corresponds to 113 OFDM tones,and the combination of the 3 tone blocks corresponds to a 5 MHz system.In this exemplary embodiment, beacon signals are transmitted by a BSSinto each tone block and beacons are communicated at a power level withrespect to the tier 0 power level; however, pilot signals and user datasignals may or may not be transmitted into a given tone block andpilot/user data signals are transmitted by a base station sector at apower level with respect to power tier level of the corresponding toneblock. Each base station sector transmits one beacon signal per toneblock per beaconslot. In this exemplary embodiment, the sector typedetermines which tone block is the tier 0 tone block; tier I and tier 2tone blocks, when used, are also determined by association with a sectortype.

Block 8050 indicates that for BSS 0 8012 of base station 1 8002: (i)tone block 0 is associated with tier power level 0 and beacon, pilot anduser data signals are communicated in tone block 0, (ii) tone block 1 isassociated with tier power level 1 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 isassociated with tier power level 2 and beacon, pilot and user datasignals are communicated in tone block 2. Block 8052 indicates that forBSS 1 8014 of base station 1 8002: (i) tone block 0 is associated withtier power level 2 and beacon, pilot and user data signals arecommunicated in tone block 0, (ii) tone block 1 is associated with tierpower level 0 and beacon, pilot and user data signals are communicatedin tone block 1, (iii) tone block 2 is associated with tier power level1 and beacon, pilot and user data signals are communicated in tone block2. Block 8054 indicates that for BSS 2 8016 of base station 1 8002: (i)tone block 0 is associated with tier power level 1 and beacon, pilot anduser data signals are communicated in tone block 0, (ii) tone block 1 isassociated with tier power level 2 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 isassociated with tier power level 0 and beacon, pilot and user datasignals are communicated in tone block 2.

Block 8056 indicates that for BSS 0 8024 of base station 2 8004: (i)tone block 0 is associated with tier power level 0 and beacon, pilot anduser data signals are communicated in tone block 0, (ii) tone block I isassociated with tier power level 1 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 isassociated with tier power level 2 and beacon, pilot and user datasignals are communicated in tone block 2. Block 8058 indicates that forBSS 1 8026 of base station 2 8004: (i) tone block 0 is associated withtier power level 2 and beacon, pilot and user data signals arecommunicated in tone block 0, (ii) tone block 1 is associated with tierpower level 0 and beacon, pilot and user data signals are communicatedin tone block 1, (iii) tone block 2 is associated with tier power level1 and beacon, pilot and user data signals are communicated in tone block2. Block 8060 indicates that for BSS 2 8028 of base station 2 8004: (i)tone block 0 is associated with tier power level 1 and beacon, pilot anduser data signals are communicated in tone block 0, (ii) tone block 1 isassociated with tier power level 2 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 isassociated with tier power level 0 and beacon, pilot and user datasignals are communicated in tone block 2.

Block 8062 indicates that for BSS 0 8036 of base station 3 8006: (i)tone block 0 is associated with tier power level 0 and beacon, pilot anduser data signals are communicated in tone block 0, (ii) tone block 1 isassociated with tier power level 1 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 is used forbeacon signaling but not used for pilot and user data signaling. Block8064 indicates that for BSS 1 8038 of base station 3 8006: (i) toneblock 0 is used for beacon signaling but is not used for pilot and userdata signaling, (ii) tone block 1 is associated with tier power level 0and beacon, pilot and user data signals are communicated in tone block1, (iii) tone block 2 is used for beacon signaling but is not used forpilot and user data signaling. Block 8066 indicates that for BSS 2 8040of base station 3 8006: (i) tone block 0 is used for beacon signalingbut is not used for pilot and user data signaling, (ii) tone block 1 isused for beacon signaling but is not used for pilot and user datasignaling, (iii) tone block 2 is associated with tier power level 0 andbeacon, pilot and user data signals are communicated in tone block 2.

Block 8068 indicates that for the BSS of base station 4 8008: (i) toneblock 0 is associated with tier power level 0 and beacon, pilot and userdata signals are communicated in tone block 0, (ii) tone block 1 isassociated with tier power level 1 and beacon, pilot and user datasignals are communicated in tone block 1, (iii) tone block 2 isassociated with tier power level 2 and beacon, pilot and user datasignals are communicated in tone block 2.

FIG. 14 is a drawing of the exemplary system 8000, described in FIGS. 12and 13, which includes exemplary signaling received and processed by WT8010 for the purposes of illustrating exemplary beacon ratio reportmethods in accordance with various embodiments. In the example of FIG.14, the wireless terminal 8010 has a wireless connection 8070 with BSS8016 using tone block 1 physical attachment point. In regard to a beaconratio report communicated over connection 8070, BSS 8016 is the servingBSS, sometimes denoted as BSS₀. In this example from the perspective ofWT 8012, BSSs 8012, 8026, 8036, 8008 represent interfering base stationsectors, sometimes denoted BSS_(i)s.

From the serving BSS 8016, the wireless terminal receives and processesbeacon signals 8078 and pilot tone signal 8076 communicated in toneblock 1. Note that WT 1 8010 is timing synchronized with respect to theBSS 8016 tone block 1 attachment point and thus can accurately measurethe pilot channel. From each interfering BSS (8012, 8026, 8036, 8008),the wireless terminal 8010 receives and processes beacon signals (8072,8082, 8086, 8090), respectively, communicated in tone block 1. Thebeacon signals, e.g., using a single tone transmitted at a relativelyhigh per tone transmit power level in comparison to other downlinkbroadcast signals such as pilot signals and having a duration of twoconsecutive OFDM symbol transmission time periods are more easilydetectable, e.g., at longer ranges, than pilot signals and do notrequire precise timing synchronization to be accurately measured. Inaddition uplink load factor information signals (8080, 8074, 8084, 8088,8092) are communicated from each of the BSSs (8016, 8012, 8026, 8036,8008), respectively. These uplink load factor information signals (8080,8074, 8084, 8088, 8092) are communicated as broadcast signals, but mayor may not be successfully recovered, e.g., as their per tonetransmission power level is lower than a beacon's. Where an uplinkloading factor can not be successfully recovered, a default value, e.g.,a value of 1, is used in the beacon ratio report calculation.

Exemplary generic beacon ratio report generation will now be described,the generated generic beacon ratio report being communicated overconnection 8070 via a dedicated control channel segment.

The serving BSS, BSS₀ is BSS 8016. PP₀ is the wireless terminal measuredpower of received pilot signals 8076. Interfering BSS₁ is BSS 8012, andPB₁ is the measured power of received beacon signal 8072. InterferingBSS₂ is BSS 8026, and PB₂ is the measured power of received beaconsignal 8082. Interfering BSS₃ is BSS 8036, and PB₃ is the measured powerof received beacon signal 8086. Interfering BSS₄ is BSS 8008, and PB₄ isthe measured power of received beacon signal 8090.l Uplink loadingfactors (b0, b1, b2, b3, b4) are recovered, if successfully recovered,from signals (8080, 8074, 8084, 8088, 8092), respectively. The value ofeach b is greater than or equal to zero and less than or equal to 1. Ifa given b can not be recovered a default value of 1 is used. Indicatorfunction I₁=1 since tone block 1 is used by BSS 8102 for pilot and userdata signaling. Indicator function I₂=1 since tone block 1 is used byBSS 8026 for pilot and user data signaling. Indicator function I₃=0since tone block 1 is not used by BSS 8036 for pilot and user datasignaling. Indicator function I₄=1 since tone block 1 is used by BSS8008 for pilot and user data signaling.

K is the ratio of the per-tone transmission power of the beacon channelto the pilot channel for a tier 0 tone block, which a constant for thesystem. Z₀=bssPowerbackoff02 since tone block 1 of BSS 8016 is a tier 2tone block. Z₁=bssPowerbackoff01 since tone block 1 of BSS 8012 is atier 1 tone block. Z₂=1 since tone block 1 of BSS 8026 is a tier 0 toneblock. Z₃ is not relevant since I₃=0. Z₄=bssPowerbackoff01 since toneblock 1 of BSS 8008 is a tier I tone block.

In the general case with n interfering base station sectors beingconsidered, a first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁*I₁+G₂b₂/Z₂*I₂+G₃b₃/Z₃*I₃+G₄b₄/Z₄*I₄+ . . .G_(n)b_(n)/Z_(n)*I_(n)) and a second type of generic beacon ratioreport=(b₀/Z₀)/(max(G₁b₁/Z₁*I₁, G₂b₂/Z₂*I₂, G₃b₃/Z₃*I₃, G₄b₄/Z₄*I₄, . .. , G_(n)b_(n)/Z_(n)*I_(n))) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀).G ₃ =PB ₃ /PB ₀ or PB ₃/(PP ₀ *K*Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀)....G _(n) =PB _(n) /PB ₀ or PB _(n)/(PP ₀ *K*Z ₀).For the specific case of FIG. 14 with 4 interfering base station sectorsbeing considered, the first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁*I₁+G₂b₂/Z₂*I₂+G₃b₃/Z₃*I₃+G₄b_(4/)Z₄*I₄) and thesecond type of generic beacon ratio report=(b₀/Z₀)/(max(G₁b₁/Z₁*I₁,G₂b₂/Z₂*I₂, G₃b₃/Z₃*I₃, G₄b₄/Z₄*I₄)) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀).G ₃ =PB ₃ /PB ₀ or PB ₃/(PP ₀ *K*Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).In addition since I₁=1, I₂=1, I₃=0, and I₄=1 the generic beacon ratioreport equation is reduced to: first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁+G₂b₂/Z₂+G₄b₄/Z₄) and second type of genericbeacon ratio report=(b₀/Z₀)/(max(G₁b₁/Z₁, G₂b₂/Z₂, G₄b₄/Z₄)) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).

FIG. 15 is a drawing of the exemplary system 8000, described in FIGS. 12and 13, which includes exemplary signaling received and processed by WT8010 for the purposes of illustrating exemplary beacon ratio reportmethods in accordance with various embodiments. In the example of FIG.15, the wireless terminal 8010 has two concurrent wireless connections,a first wireless connection 8070 with BSS 8016 using tone block 1physical attachment point and the second physical connection is with BSS8026 using tone block 1 physical attachment point. In regard to a beaconratio report communicated over connection 8070, BSS 8016 is the servingBSS, sometimes denoted as BSS₀, and BSSs 8012, 8026, 8036, 8008represent interfering base station sectors, sometimes denoted BSS_(i)s.In regard to a beacon ratio report communicated over connection 8071,BSS 8026 is the serving BSS, sometimes denoted as BSS_(0.), and BSSs8012, 8016, 8036, 8008 represent interfering base station sectors,sometimes denoted BSS_(i)s.

The same signals previously described with respect to FIG. 14 can usedby WT 8010 in generating a beacon ratio report for connection 8070. Inaddition, pilot signals 8083 in tone block I from BSS 8026 can be usedby WT 8010 in generating a beacon ratio report for connection 8070.

In the general case with n interfering base station sectors beingconsidered, a first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁*I₁+G₂b₂/Z₂*I₂+G₃b₃/Z₃*I₃+G₄b₄/Z₄*I₄+ . . .G_(n)b_(n)/Z_(n)*I_(n)) and a second type of generic beacon ratioreport=(b₀/Z₀)/(max(G₁b₁/Z₁*I₁, G₂b₂/Z₂*I₂, G₃b₃/Z₃*I₃, G₄b₄/Z₄*I₄, . .. , G_(n)b_(n)/Z_(n)*I_(n))) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀) or (PP ₁ *Z ₁)/(PP ₀ *Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀) or (PP ₂ *Z ₂)/(PP ₀ *Z ₀).G ₃ =PB ₃ /PB ₀ or PB ₃/(PP ₀ *K*Z ₀) or (PP ₃ *Z ₃)/(PP ₀ *Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀) or (PP ₄ *Z ₄)/(PP ₀ *Z ₀)....G _(n) =PB _(n) /PB ₀ or PB _(n)/(PP ₀ *K*Z ₀) or (PP _(n) *Z _(n))/(PP₀ *Z ₀).

For the specific case of FIG. 15 with 4 interfering base station sectorsbeing considered with respect to connection 1 8070, the first type ofgeneric beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁*I₁+G₂b₂/Z₂*I₂+G₃b₃/Z₃*I₃+G₄b₄/Z₄*I₄) and thesecond type of generic beacon ratio report=(b₀/Z₀)/(max(G₁b₁/Z₁*I₁,G₂b₂/Z₂*I₂, G₃b₃/Z₃*I₃, G₄b₄/Z₄*I₄)) where

where BSS 8016 is BSS₀, BSS 8012 is BSS₁, BSS 8026 is BSS₂, BSS 8036 isBSS₃ and BSS 8008 is BSS₄, and taking into account the availability ofpilot signal information,G ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀) or (PP ₂ *Z ₂)/(PP ₀ *Z ₀).G ₃ =PB ₃ /PB ₀ or PB ₃/(PP ₀ *K*Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).In addition since I₁=1, I₂=1, I₃=0, and I₄=1 the generic beacon ratioreport equation is reduced to: first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁+G₂b₂/Z₂+G₄b₄/Z₄) and second type of genericbeacon ratio report=(b₀/Z₀)/(max(G₁b₁/Z₁, G₂b₂/Z₂, G₄b₄/Z₄)) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀) or (PP ₂ *Z ₂)/(PP ₀ *Z ₀)G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).

For the specific case of FIG. 15 with 4 interfering base station sectorsbeing considered with respect to connection 2 8071, the first type ofgeneric beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁*I₁+G₂b₂/Z₂*I₂+G₃b₃/Z₃*I₃+G₄b₄/Z₄*I₄)) and thesecond type of generic beacon ratio report =(b₀/Z₀)/(max(G₁b₁/Z₁*I₁,G₂b₂/Z₂*I₂, G₃b₃/Z₃*I₃, G₄b₄/Z₄*I₄)) where

where BSS 8026 is BSS₀, BSS 8016 is BSS₁, BSS 8012 is BSS₂, BSS 8036 isBSS₃ and BSS 8008 is BSS₄, and taking into account the availability ofpilot signal information,G ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀) or (PP ₁ *Z ₁)/(PP ₀ *Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀).G ₃ =PB ₃ /PB ₀ or PB ₃/(PP ₀ *K*Z ₀).G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).In addition since I₁=1, I₂=1, I₃=0, and I₄=1 the generic beacon ratioreport equation is reduced to: first type of generic beacon ratioreport=(b₀/Z₀)/(G₁b₁/Z₁+G₂b₂/Z₂+G₄b₄/Z₄) and second type of genericbeacon ratio report=(b₀/Z₀)/(max(G₁b₁/Z₁, G₂b₂/Z₂, G₄b₄/Z₄)) whereG ₁ =PB ₁ /PB ₀ or PB ₁/(PP ₀ *K*Z ₀) or (PP ₁ *Z ₁)/(PP ₀ *Z ₀).G ₂ =PB ₂ /PB ₀ or PB ₂/(PP ₀ *K*Z ₀)G ₄ =PB ₄ /PB ₀ or PB ₄/(PP ₀ *K*Z ₀).

In some embodiments, a wireless terminal attempts to obtain a channelgain ratio, e.g. a G_(i), using pilot signals if reliable pilot signalinformation can be recovered from the two sources. If that is notpossible, the wireless terminal attempts to obtain a channel gain ratiousing pilot signals from the serving base station sector and beaconsignals from the other base station sector.

FIG. 16 is a drawing of the exemplary system 8000, described in FIGS. 12and 13, which includes exemplary signaling received and processed by WT8010 for the purposes of illustrating exemplary beacon ratio reportmethods in accordance with various embodiments. In the example of FIG.16, the wireless terminal 8010 has a first wireless connection 8001 withBSS 8016 using tone block 1 physical attachment point and a secondconcurrent wireless connection 8003 with BSS 8026 using tone block 2physical attachment point. In regard to a beacon ratio reportcommunicated over connection 8001, BSS 8016 is the serving BSS,sometimes denoted as BSS₀ and BSSs 8012, 8026, 8036, 8008 representinterfering base station sectors sometimes referred denoted as BSS_(i)s,e.g., BSS₁, BSS₂, BSS₃, BSS₄. In regard to a beacon ratio reportcommunicated over connection 8003, BSS 8026 is the serving BSS,sometimes denoted as BSS₀, and BSSs 8012, 8016, 8036, 8008 representinterfering base station sectors, sometimes denoted BSS_(i)s , e.g.,BSS₁, BSS₂, BSS₃, BSS₄.

From BSS 8016, the wireless terminal receives and processes beaconsignals 8011 communicated in both tone block 1 and tone block 2 andpilot tone signal 8009 communicated in tone block 1. Note that WT 1 8012is timing synchronized with respect to the BSS 8016 tone block 1attachment point and thus can accurately measure the pilot channel. FromBSS 8026, the wireless terminal receives and processes beacon signals8017 communicated in both tone block I and tone block 2 and pilot tonesignal 8015l communicated in tone block 2. Note that WT 1 8010 is timingsynchronized with respect to the BSS 8026 tone block 2 attachment pointand thus can accurately measure the pilot channel. From each interferingBSS (8012, 8036, 8008), the wireless terminal 8010 receives andprocesses beacon signals (8005, 8021, 8025), respectively, communicatedin tone block 1 and tone block 2. In addition uplink load factorinformation signals (8013, 8007, 8019, 8023, 8027) are communicated fromeach of the BSSs (8016, 8012, 8026, 8036, 8008), respectively. Theseuplink load factor information signals (8013, 8007, 8019, 8023, 8027)are communicated as broadcast signal, but may or may not be successfullyrecovered, e.g., as their per tone transmission power level is lowerthan a beacon's. Where an uplink loading factor can not be successfullyrecovered, a default value, e.g., a value of 1, is used in the beaconratio report calculation.

In the example of FIG. 16, the two connections use different toneblocks. Gain ratios computed for beacon ratio reports to be communicatedover connection 1 8001 can use received pilot tone signals 8009 of toneblock 1 from base station sector 8016 and received beacon signals fromthe other base station sectors. Gain ratios computed for beacon ratioreports to be communicated over connection 2 8003 can use received pilottone signals 8015 of tone block 2 from base station sector 8026 andreceived beacon signals from the other base station sectors.

In some exemplary embodiments, with respect to a base station sector,the OFDM signals from one tone block are accurately synchronized withrespect to the OFDM symbols from another tone block. Consider that theBSS uses a common transmitter and generates a single OFDM symbolcorresponding to the three tone blocks, e.g. a single OFDM symbolincluding 339 tones comprising three tone blocks of 113 tones each. Insome such embodiments, gain ratios computed for beacon ratio reports tobe communicated over connection 1 8001 can use received pilot tonesignals of tone block 1 from base station sector 8016, received pilottone signal of tone block 1 from BSS 8026 and received beacon signalsfrom the other base station sectors; gain ratios computed for beaconratio reports to be communicated over connection 2 8003 can use receivedpilot tone signals of tone block 2 from base station sector 8026,received pilot tone signal of tone block 2 from BSS 8016 and receivedbeacon signals from the other base station sectors.

FIG. 17, comprising the combination of FIG. 17A, FIG. 17B, FIG. 17C, andFIG. 17D is a flowchart 5500 of an exemplary method of operating awireless terminal, e.g., mobile node, in accordance with variousembodiments. Operation starts in step 5502, where the wireless terminalis powered on and initialized. Operation proceeds from step 5502 to step5504, step 5506 and, via connecting node A 5505 to step 5508.

In step 5504, the wireless terminal is operated to receive beacon andpilot signals corresponding to a first current base station connection.Operation proceeds from step 5504 to step 5510. In step 5510, thewireless terminal measures the power of the received beacon signal (PB₀)and received pilot channel signals (PP₀) for the first current basestation sector connection. Operation proceeds from step 5510 to step5512. In step 5512, the wireless terminal derives first currentconnection base station sector transmitter information, e.g., aBSS_slope and a BSS_sector type from the received beacon signal. Step5512 includes sub-step 5513. In sub-step 5513, the wireless terminaldetermines a power transmission tier level associated with the firstcurrent connection base station sector and tone block being used.

In step 5506, the wireless terminal receives beacon signals from one ormore interfering base station sectors to which the wireless terminaldoes not have a current connection and/or receives beacon and pilotsignals from one or more interfering base station sectors to which thewireless terminal has a current connection. Operation proceeds from step5506 to step 5514 for each interfering base station sector (BSS_(i)) towhich the wireless terminal has a current connection. Subsequentoperations 5514, 5518, 5520 are performed for each such interfering basestation sector, e.g., interfering base station sector _(i) (BSS_(i)).Operation proceeds from step 5506 to step 5516 for each interfering basestation sector (BSS_(i)) to which the wireless terminal does not have acurrent connection. Subsequent operations 5516, 5522, 5524 are performedfor each such interfering base station sector, e.g., interfering basestation sector _(i) (BSS_(i)).

In step 5514, the wireless terminal measures the power of the receivedbeacon signal (PB_(i)) and received pilot channel signals (PP_(i)) forthe interfering current base station sector connection. Operationproceeds from step 5514 to step 5518. In step 5518, the wirelessterminal derives interfering current connection base station sectortransmitter information, e.g., a BSS_slope and a BSS_sector type fromthe received beacon signal. Step 5518 includes sub-step 5519. Insub-step 5519, the wireless terminal determines a power transmissiontier level associated with the interfering current connection basestation sector and tone block being used.

Operation proceeds from steps 5512 and step 5518 to step 5520 viaconnecting node B 5521. In step 5520 the wireless terminal computes achannel gain ratio using the method of sub-step 5538 or the method ofsub-step 5540 or the method of sub-step 5541. In sub-step 5538, thewireless terminal uses beacon signal information to compute the channelgain ratio, G_(i). Sub-step 5538 includes sub-step 5542, where thewireless terminal computes G_(i)=PB_(i)/PB₀.

In sub-step 5540, the wireless terminal uses beacon signal informationand pilot signal information to compute the channel gain ratio G_(i).Sub-step 5540 includes sub-step 5544. In sub-step 5544, the wirelessterminal computes G_(i)=PB_(i)/(PP₀* K * Z₀), where K=per tonetransmitter power beacon reference level for a tier 0 tone block/pertone transmitter pilot signal reference level for a tier 0 tone block,and Z₀=power scale factor associated with the a power transmission tierlevel of the tone block for the first current base station sectorconnection transmitter tone block.

In sub-step 5541, the wireless terminal uses pilot signal information tocompute the channel gain ratio G_(i). Sub-step 5541 includes sub-step5546. In sub-step 5546, the wireless terminal computes G_(i)=(PP_(i)*Z_(i))/(PP₀ * Z₀), where Z₀=power scale factor associated with the powertransmission tier level of the tone block for the first current basestation sector connection transmitter tone block and Z_(i)=power scalefactor associated with the a power transmission tier level of the toneblock for the BSS connection transmitter tone block. Operation proceedsfrom step 5520 via connecting node D 5534 to step 5536, where thewireless terminal generates one or more interference reports.

In step 5516, the wireless terminal measures the power of receivedbeacon signal (PB_(i)) for the interfering base station sector.Operation proceeds from step 5516 to step 5522. In step 5522, thewireless terminal derives interfering base station sector transmitterinformation, e.g., a BSS_slope and a BSS_sector type from the receivedbeacon signal. Step 5522 includes sub-step 5523. In sub-step 5523, thewireless terminal determines a power transmission tier level associatedwith an interfering base station sector and tone block being used.

Operation proceeds from steps 5512 and step 5522 to step 5524 viaconnecting node C 5525. In step 5524 the wireless terminal computes achannel gain ratio using the method of sub-step 5526 or the method ofsub-step 5528.

In sub-step 5526, the wireless terminal uses beacon signal informationto compute the channel gain ratio, G_(i). Sub-step 5526 includessub-step 5530, where the wireless terminal computes G_(i)=PB_(i)/PB₀.

In sub-step 5528, the wireless terminal uses beacon signal informationand pilot signal information to compute the channel gain ratio G_(i).Sub-step 5528 includes sub-step 5532, where the wireless terminalcomputes G_(i)=PB_(i)/(PP₀ * K * Z₀), where K=per tone transmitter powerbeacon reference level for a tier 0 tone block/per tone transmitterpilot signal reference level for a tier 0 tone block, and Z₀=power scalefactor associated with the a power transmission tier level of the toneblock for the current base station sector connection transmitter toneblock.

Operation proceeds from step 5524 via connecting node D 5534 to step5536, where the wireless terminal generates one or more interferencereports.

Returning to step 5508, in step 5508 the wireless terminal is operatedto receive broadcast load factor information signals from the firstcurrent serving base station sector transmitter and from interferingbase station sector transmitters. For each base station sector underconsideration, operation proceeds to step 5548. In step 5548 thewireless terminal determines whether or not the load factor wassuccessfully recovered from the received signal. If the load factor wassuccessfully recovered from the received signal operation proceeds tostep 5550, where the wireless terminal stores the load factor. Forexample load factor b₀=the load factor for the current first servingbase station sector, and load factor b_(k)=the load factor forinterfering base station section k. If the load factor was notsuccessfully recovered from the received signal then operation proceedsto step 5552, where the wireless terminal sets the load factor to 1.Load factors (b₀ 5554, b₁ 5556, . . . , b_(k) 5558, . . . bn 5560) areobtained, with each load factor being sourced from one of steps 5550 andstep 5552.

Returning to step 5536, in step 5536 the wireless terminal generates oneor more interference reports. Step 5536 includes sub-step 5562 andsub-step 5564. In sub-step 5562, the wireless terminal generates aspecific type report conveying interference by a specific interferingbase station sector to the first serving base station sector. Step 5562includes sub-step 5566. In sub-step 5566, the wireless terminal computesthe report value=(b₀/Z₀)/(G_(k) * b_(k)/Z_(k)), where b₀ is the loadingfactor of the current serving BSS and b_(k) is the loading factor if aninterfering BSS to which the report corresponds, G_(k)=G_(i) for i=k,and Z₀ is the power scale factor associated with the power transmissiontier level of the tone block for the current first BSS connectiontransmitter tone block, and Z_(k) is the power scale factor associatedwith the power transmission tier level of the tone block for theinterfering base station sector to which the report corresponds.

In sub-step 5564, the wireless terminal generates a generic type reportconveying information of interference by one or more interfering BSSs tothe serving first current BSS, e.g., using information from each of themeasured beacon signals of interfering base station sectors includingusing load factor information and power scale factor information. Fouralternative exemplary computations for a generic type report areincludes as sub-steps 5570, 5572, 5574, 5576. An exemplary embodiment ofa generic type report, e.g., in an exemplary single carrier operationembodiment, is b₀/(Σ_(k)G_(k) * b_(k)). The summation is over each ofthe interfering BBS_(k) that the wireless terminal can detect for thebeacon or pilot signal. Another exemplary embodiment of a generic typereport, e.g., in a single carrier operation embodiment, is b₀/(max_(k)(G_(k) * b_(k))). Another exemplary embodiment of a generic type report,e.g., in a exemplary multi-carrier, e.g., three carrier, operationembodiment, is (b₀/Z₀)/(Σ_(k) (I_(k) * G_(k) * b_(k)/Z_(k))), whereI_(k) is an indicator function of whether the uplink of the BSS_(k) isactive in the current tone block: I_(k)=1 if the uplink of the BSS_(k)is active; I_(k)=0 if the BSS_(k) is inactive in the current tone block.The summation is over each of the interfering BBS_(k) that the wirelessterminal can detect for the beacon or pilot signal. Another exemplaryembodiment of a generic type report, e.g., in an exemplarymulti-carrier, e.g., three carrier, operation embodiment, is(b₀/Z₀)/(max_(k) (I_(k) * G_(k *) b_(k)/Z_(k))), where I_(k) is anindicator function of whether the uplink of the BSS_(k) is active in thecurrent tone block: I_(k)=1 if the uplink of the BSS_(k) is active;I_(k)=0 if the BSS_(k) is inactive in the current tone block.

In some embodiments, step 5536 includes quantization. For example, anexemplary beacon ratio report conveys 4 information bits representingone of 16 levels ranging from −4 dBs to 28 dBs. Table 1100 of FIG. 11for an exemplary 4-bit downlink beacon ratio report (DLBNR4) is such arepresentation.

Operation proceeds from step 5536 to step 5568 where the wirelessterminal is operated to transmit the report to the first current servingbase station sector serving as the current attachment point for thewireless terminal. In some embodiments, the transmission of a report isin response to a request from the serving base station sector. In someembodiments, the type of report transmitted, e.g., specific or generic,is in response to received signaling from a base station sectoridentifying the type of report. In some embodiments, the transmission ofa particular specific type report reporting on interference associatedwith a particular base station sector is in response to a received basestation signal identifying the particular base station sector. Invarious embodiments, interference reports are transmitted periodicallyin accordance with a reporting schedule being followed by the wirelessterminal, e.g., as part of dedicated control channel structure. In somesuch embodiments, for at least some of the interference reportstransmitted, the base station does not signal any report selectioninformation to select the report. In some embodiments, the base stationalternates between calculating between two types of generic beacon ratioreports, e.g., a first type using a summation of information from eachof the received interfering BSSs, and a second type based on informationfrom the single worst interfering BSS, as a function of current positionin a recurring timing structure. For example, the first type of genericbeacon ratio report is calculated when the beacon slot index is evenwithin a ultraslot, and the second type of generic beacon ratio reportis calculated when the beacon slot index is odd within the ultra slot.In some embodiments, the WT only sends generic beacon ratio reports bydefault and only sends a specific beacon ratio report when request to doso by the base station.

In some embodiments, the system includes a plurality of powertransmission tier levels, e.g., three, with a different power scalefactor associated with each tier level. For example, in one exemplaryembodiment a power scale factor of 0 dB is associated with a tier level0 tone block, while a power scale factor of 6 dB is associated with atier 1 level tone block, and a power scale factor of 12 dB is associatedwith a tier 2 tone block. In some embodiments, each attachment pointcorresponds to a base station sector transmitter and a tone block, andeach attachment point BSS transmitter tone block may be associated witha power transmission tier level. In some embodiments there are aplurality of downlink tones blocks, e.g., three tone block (tone block0, tone block 1, tone block 2) each having 113 contiguous evenly spacedtones. In some embodiments, the same tone block, e.g., tone block 0,used different base station sector transmitters, has a different powertransmission tier level associated with the different base stationsector transmitters. A wireless terminal, identifying a particularattachment point, corresponding to a base station sector transmitter andtone block, e.g., from information conveyed via its beacon signal usingtone location and/or time position with a recurring transmissionpattern, can used stored information to associate the identifiedattachment point with a particular power transmission tier level andpower scale factor for a particular tone block.

In some embodiments, the loading factor, e.g., b_(k), is a value greaterthan or equal to 0 and less than or equal to one. In some embodiments,the value is communicated from a base station sector to a wirelessterminal represents one of a plurality of levels, e.g., 0 dB, −1 dB, −2dB, −3 dB, −4 dB, −6 dB, −9 dB, -infinity dB. Table 950 of FIG. 10illustrates exemplary uplink loading factor information that may becommunicated by a base station sector via a downlink broadcast channel.

In some embodiments, the beacon signals are transmitted at the samepower from a base station sector transmitter irrespective of powertransmission tier associated with the tone block being used; however,other downlink signals, e.g., pilot signals, are affected by the powertransmission tier associated with the tone block for the base stationsector transmitter. In some embodiments, the parameter K is at valuegreater than or equal to 6 dB. For example in one exemplary embodimentthe parameter K=23.8 dB −7.2 dB=16.6 dB.

FIG. 18 is a drawing 1800 of exemplary timing structure information andcorresponding interference reporting information, e.g., beacon ratioreport reporting information, for an exemplary embodiment. The exemplarytiming structure includes uplink ultraslots as indicated by row 1802showing uplink ultraslot with index=0 followed by uplink ultraslot withindex=1. In the exemplary embodiment, each ultaslot includes 18 indexedbeaconslots as indicated by row 1804. Each beaconslot includes, e.g.,912 consecutive OFDM symbol transmission time periods. In this exemplaryembodiment, a wireless terminal can report two different types of beaconratio reports to a serving base station sector, e.g., via dedicatedcontrol channel segments, the first type of beacon ratio report being ageneric beacon ratio report and the second type of beacon ratio reportbeing a specific beacon ratio report, sometimes referred to as a specialbeacon ratio report. The first type of beacon ratio report is a genericbeacon ratio report and two sub-types of generic beacon ratio reportsare used. A first sub-type of generic beacon ratio report determines areport value as a function of the summation of one or more interferingbase stations sectors. A second sub-type of generic beacon ratio reportdetermines a report value as a function of a maximum, e.g., the worstcase individual base station sector in terms of the interference value.As indicated by row 1806, the sub-type of generic beacon ratio report touse is a function of the beaconslot index. For even values of thebeaconslot index (0, 2, 4, 6, 8, 10, 12, 14, 16) a wireless terminal,when transmitting a generic beacon ratio report uses a summationfunction to determine the report. For odd values of the beaconslot index(1, 3, 5, 7, 9, 11, 13, 15, 17) a wireless terminal, when transmitting ageneric beacon ratio report uses a maximum function to determine thereport. Row 1808 indicates that a wireless terminal, when transmitting aspecific beacon ratio report communicates a report corresponding to abase station sector identified in a request and having a sector typewhich is a function of the beaconslot index value. For example, considerthat three different sector types are used (sector type 0, sector type1, and sector type 2). A request signal from the serving base stationsector requesting specific type of beacon ratio reports may include acell identifier value, e.g., a slope value, and the uplink timingstructure in which the report is communicated may determine the sectortype. For example, for beaconslots with index=(0, 3, 6, 9, 12, 15) awireless terminal, when reporting a specific beacon ratio report,reports a specific beacon ratio report relating the serving base stationsector to another base station sector identified by a communicated cellidentifier value and having sector type=0. For beaconslots withindex=(1, 4, 7, 10, 13, 16) a wireless terminal, when reporting aspecific beacon ratio report, reports a specific beacon ratio reportrelating the serving base station sector to another base station sectoridentified by a communicated cell identifier value and having sectortype=1. For beaconslots with index=(2, 5, 8, 11, 14, 17) a wirelessterminal, when reporting a specific beacon ratio report, reports aspecific beacon ratio report relating the serving base station sector toanother base station sector identified by a communicated cell identifiervalue and having sector type=2.

It should be observed that by implementing this predetermined timingstructure based reporting format, understood by both the base stationand the wireless terminal, the system supports a variety of reportingformats while limiting the amount of signaling overhead. In addition, itshould be observed that for the specific beacon ratio report,identification of a base station sector of interest is obtained partlyby information included in a request signal and partly by position inthe uplink timing structure, thus fewer bits are needed for overheadsignaling to identify a base station sector of interest.

FIG. 19 illustrates in drawing 1900, for an exemplary embodiment,exemplary beacon ratio report request downlink signaling and exemplaryuplink beacon ratio report signaling. In FIG. 1900, base station sector1902, a current attachment point for wireless terminal 1904, sends adownlink traffic channel control signal 1906 including information in arequest for beacon ratio report field 1908, e.g., as part of downlinktraffic control channel flash signal. In some embodiments, the signalincluding the request for beacon ratio report field is a broadcastsignal, e.g., intended for use by multiple wireless terminals. Thus, anindividual control signal is broadcast for multiple connected wirelessterminals to use thus reducing the level of overhead control signalingthat would otherwise be needed if each wireless terminal wasindividually controlled with respect to the type of interference reportto send. In some embodiments, a single request for beacon ratio reportdownlink signal may correspond to multiple uplink interference reportsto be communicated by a wireless terminal. In some embodiments, a singlerequest for beacon ratio report downlink signal corresponds to a singleuplink interference report for an individual wireless terminal. In someembodiments, a single request for beacon ratio report downlink signalcorresponds to a single interference uplink report for each of aplurality of different wireless terminals. The request for beacon ratioreport field includes a value indicating the request. Table 1901 is anexemplary request for beacon ratio report field reporting format thatmay be used by BSS 1902 and WT 1904. First column 1918 of table 1901indicates values conveyed by the report; second column 1920 includes theinformation conveyed by the corresponding value. If the value is a zero,the wireless terminal is to report a generic beacon ratio report. If thevalue is a non-zero positive integer, the wireless terminal is to reporta specific beacon ratio report, and the value corresponds to a cellidentifier parameter, e.g., a slope value, used by the base stationsector of interest. The slope value is, in some embodiments, a valuecorresponding to slope of pilot tone signals. However, in someembodiments, multiple base station sectors within the same cell use thesame value for slope, and thus uplink timing information is also used todetermine the particular base station sector of interest to be used fora particular specific beacon ratio report, e.g., timing informationindicated by rows 1808.

In some other embodiments, a wireless terminal transmits a first type ofreport by default, and a second type of report if a request for beaconratio report signal is communicated. For example, generic beacon ratioreports may be communicated by default, and if a base station wantsspecific type beacon ratio reports to be communicated, then the basestation communicates a request for beacon ratio report signal includingcell identifier information.

Dedicated control channel segment signal 1910 includes a beacon ratioreport 1912 in accordance with request information and uplink timingstructure information. Dedicated control channel segment signal 1914includes a beacon ratio report 1916 in accordance with requestinformation and uplink timing structure information. For example,consider that request field 1908 conveyed a value of 0, that report 1912corresponds to a beacon ratio report communicated during a beaconslotwith index=0, and that report 1916 corresponds to a beacon ratio reportcommunicated during a beaconslot with index=1. Beacon ratio report 1912is a generic beacon ratio report using a summation function to computethe report value, the report relating detected base station sectors ofthe same tone block to the serving base station sector; beacon ratioreport 1916 is a generic beacon ratio report using a maximum function tocompute the report value, the report relating detected base stationsectors of the same tone block to the serving base station sector. Nowconsider that request field 1908 conveyed a value of 1, that report 1912corresponds to a beacon ratio report communicated during a beaconslotwith index=0, and that report 1916 corresponds to a beacon ratio reportcommunicated during a beaconslot with index=1. Beacon ratio report 1912is a specific beacon ratio report relating the current serving basestation sector attachment point to a local base station sectoridentified by slope value=1 and having a sector type=0 and using thesame tone block as the serving base station sector; beacon ratio report1916 is a specific beacon ratio report relating the current serving basestation sector attachment point to a local base station sectoridentified by slope value=1 and having a sector type=1 and using thesame tone block as the serving base station sector.

FIG. 20 is a drawing of an exemplary communications system 2000implemented in accordance with various embodiments. Exemplarycommunications system 2000 includes a plurality of base stations (BS 12001, BS 2 2002, BS 3 2003, BS 4 2004, BS 5 2005, BS 6 2006, BS 7 2007,BS 8 2008, BS 9 2009, BS 10 2010) coupled together via a backhaulnetwork. The BSs (2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,2010) are three sector base stations. BS 1 2001 includes: a first sector2012 with a slope value=2 and a sector type value=0, a second sector2014 with a slope value=2 and a sector type value=1, and a third sector2016 with a slope value=2 and a sector type value=2. BS 2 2002 includes:a first sector 2018 with a slope value=1 and a sector type value=0, asecond sector 2020 with a slope value=1 and a sector type value=1, and athird sector 2022 with a slope value=1 and a sector type value=2. BS 32003 includes: a first sector 2024 with a slope value=1 and a sectortype value=0, a second sector 2026 with a slope value=1 and a sectortype value=1, and a third sector 2028 with a slope value=1 and a sectortype value=2. BS 4 2004 includes: a first sector 2030 with a slopevalue=2 and a sector type value=0, a second sector 2032 with a slopevalue=2 and a sector type value=1, and a third sector 2034 with a slopevalue=2 and a sector type value=2. BS 5 2005 includes: a first sector2036 with a slope value=3 and a sector type value=0, a second sector2038 with a slope value=3 and a sector type value=1, and a third sector2040 with a slope value=3 and a sector type value=2. BS 6 2006 includes:a first sector 2042 with a slope value=4 and a sector type value=0, asecond sector 2044 with a slope value=4 and a sector type value=1, and athird sector 2046 with a slope value=4 and a sector type value=2. BS 72007 includes: a first sector 2048 with a slope value=5 and a sectortype value=0, a second sector 2050 with a slope value=5 and a sectortype value=1, and a third sector 2052 with a slope value=5 and a sectortype value=2. BS 8 2008 includes: a first sector 2054 with a slopevalue=6 and a sector type value=0, a second sector 2056 with a slopevalue=6 and a sector type value=1, and a third sector 2058 with a slopevalue=6 and a sector type value=2. BS 9 2009 includes: a first sector2060 with a slope value=7 and a sector type value=0, a second sector2062 with a slope value=7 and a sector type value=1, and a third sector2064 with a slope value=7 and a sector type value=2. BS 10 2010includes: a first sector 2066 with a slope value=8 and a sector typevalue=0, a second sector 2068 with a slope value=8 and a sector typevalue=1, and a third sector 2070 with a slope value=8 and a sector typevalue=2.

The exemplary communications system 2000 also includes a plurality ofwireless terminals. Exemplary WT A 2072 and exemplary WT B 2072 areshown connected to base station 5 2005 second sector 2038 via wirelesslinks (2076, 2078), respectively. Base station sector 5 2005 secondsector 2038 attachment point sends broadcast downlink traffic channelcontrol signals including a request for beacon ratio report field value,e.g., as indicated in FIG. 19. WT A 2072 is in an On state of operation,and has been allocated uplink dedicated control channel segments forcommunicating uplink control reports, some of the uplink reports are tobe interference reports, e.g., beacon ratio reports. Similarly WT B 2074is in an On state of operation, and has been allocated uplink dedicatedcontrol channel segments for communicating uplink control reports, someof the uplink reports are to be interference reports, e.g., beacon ratioreports. The WTs (2072, 2074) receive the broadcast request for beaconratio report information in determining the type of beacon ratio reportto be communicated. In some embodiments, the information is used inconjunction with timing structure information in determining theinformation to be included in an uplink interference report.

It should be observed that the slope value used as a base stationidentifier is locally unique but is not unique in the system 2000. Forexample slope value=1 is used as a cell identifier by both BS 1 2001 andBS 3 2003. However, there is no ambiguity between the WT and basestation attachment point as to which base station is the intendedtarget. By using a locally unique base station identifier, as opposed toa system unique base station identifier, in control signaling, thenumber of bits needed to represent the base station is reduced thusallowing control signaling overhead to be reduced in a system utilizinga large number of base stations. The same principle can, and in variousembodiments, are used for base stations including a large number ofsectors. For example, an exemplary five sector base station may usethree different sector types with two of the sector type values beingused twice.

FIG. 21 is a drawing 2100 illustrating exemplary downlink controlsignaling and uplink interference reporting, e.g., beacon ratioreporting, corresponding to system 2000 of FIG. 20. First row 2104includes a time line indicating when specific reporting of beacon ratioreports is possible corresponding different base station sector types.In this example, there are three different sector types (sector type 0,sector type 1, and sector type 2). In accordance with this embodiment,the reporting structure alternates between the three types, e.g., witheach block representing the time interval of a beaconslot (see FIG. 18).Second row 2106 indicates the request for beacon ratio report valueincluded in a broadcast downlink traffic control channel signal (seeFIG. 19). Third row 2108 indicates the WT A communicated report type,where G =generic report and S=specific report. Fourth row 2110indicates, for WT A specific reports, the base station and base stationsector type to be used in calculating the specific report. Fifth row2112 indicates the WT B communicated report type, where G=generic reportand S=specific report. Sixth row 2114 indicates, for WT B specificreports, the base station and base station sector type to be used incalculating the specific report.

The first value of row 2106 is a 0 indicating that the correspondinginterference reports should be generic type reports. Therefore both WT Aand WT B transmit generic uplink beacon ratio reports. The second valueof row 2096 is a 4 indicating that the corresponding reports should bespecific type reports corresponding to a local base station sector usingslope value=4. The time for the corresponding uplink beacon ratioreports is within the beaconslot used for sector type 0. Therefore theWTs transmit specific beacon ratio reports to BS 5 sector 2038 relatingbase station 6 sector type 0 sector 2042 to base station 5 sector type 1sector 2038. The third and fourth values of row 2106 are 0, andtherefore the corresponding beacon ratio reports are generic beaconratio reports. The fifth value of row 2106 is a 1 indicating that thecorresponding reports should be specific type reports corresponding to alocal base station sector using slope value=1. The time for thecorresponding uplink beacon ratio reports is within the beaconslot usedfor sector type 2. Therefore the WTs transmit specific beacon ratioreports to BS 5 sector 2038 relating base station 3 sector type 2 sector2028 to base station 5 sector 1 2038. The sixth value of row 2106 is 0,and therefore the corresponding beacon ratio reports are generic beaconratio reports. The seventh value of row 2106 is a 2 indicating that thereports should be specific type reports corresponding to a local basestation sector using slope value=2. The time for the correspondinguplink beacon ratio reports is within the beaconslot used for sectortype 0. Therefore the WTs transmit specific beacon ratio reports to BS 5sector 2038 relating base station 4 sector type 0 sector 2030 to basestation 5 sector 1 2038. The eight, ninth and tenth values of row 2106are 0, and therefore the corresponding beacon ratio reports are genericbeacon ratio reports. The eleventh value of row 2106 is a 2 indicatingthat the reports should be specific type reports corresponding to alocal base station sector using slope value=2. The time for thecorresponding uplink beacon ratio reports is within the beaconslot usedfor sector type 2. Therefore the WTs transmit specific beacon ratioreports to BS 5 sector 2038 relating base station 4 sector type 2 sector2034 to base station 5 sector 1 2038. The twelfth, thirteenth andfourteenth values of row 2096 are 0, and therefore the correspondingbeacon ratio reports are generic beacon ratio reports.

In this exemplary embodiment, there is a fixed relationship in thetiming structure between downlink control channel signals includingrequest for beacon ratio reports and corresponding uplink interferencereporting opportunities for the WTs, e.g., as indicatd by the dottedline arrows. This linkage in the timing structure, understood by bothbase station and wireless terminal, reduces overhead signaling. In thisexemplary embodiment, WT A and WT B transmit their uplink beacon ratioreports, corresponding to the same request, at different points in timein the uplink timing structure. For other embodiments and/or for otherwireless terminals the reports may be communicated concurrently, e.g.,using different tones in the tone block. In addition in someembodiments, the frequency of reporting by one WT may be different thanthe frequency of reporting by a different wireless terminal, e.g., overa given time interval as one wireless terminal may be in a differentreporting mode of operation with respect to the other wireless terminal.

Although illustrated for two exemplary wireless terminals, it is to beunderstood that, in some embodiments, the same request for beacon ratioreport broadcast control signal may be, and sometimes is utilized bymany additional wireless terminals using the base station sectorattachment point. For example, consider one exemplary embodiment inwhich a base station sector attachment point can have up to 31concurrent On state users, and each on the On state users receives adedicated control channel for transmitting uplink control channelreports including beacon ratio reports, each On-state user can receiveand utilize the same broadcast request for beacon ratio report downlinksignal.

FIG. 22 is a drawing of a flowchart 2200 of an exemplary method ofoperating a wireless terminal in accordance with various embodiments.The exemplary method starts in step 2202 where the wireless terminal ispowered on and initialized. Operation proceeds from start step 2202 tosteps 2204, 2206, 2208, and in some embodiments, step 2210. In step2204, the wireless terminal monitors to detect received broadcastsignals communicating uplink loading factors, each broadcast uplinkloading factor corresponding to an attachment point. In step 2206, thewireless terminal is operated to receive a first signal, e.g., a beaconor pilot signal, from a first attachment point. In step 2208, thewireless terminal is operated to receive a second signal, e.g., a beaconor pilot signal, from a second attachment point. In step 2210, whenperformed, the wireless terminal is operated to receive a third signal,e.g., a beacon or pilot signal, from a third attachment point.

Operation proceeds from step 2206 to step 2226, where the wirelessterminal performs a first measurement, e.g., a signal power measurement,on the received first signal. Operation proceeds from step 2208 to step2228, where the wireless terminal performs a second measurement, e.g., asignal power measurement, on the received second signal. Operationproceeds from step 2210 to step 2230, where the wireless terminalperforms a third measurement, e.g., a signal power measurement, on thereceived third signal. Operation proceeds form steps 2226, 2228 and 2230to step 2232.

Returning to step 2204, in step 2204, the wireless outputs receiveduplink loading factor information which is forwarded to be used in step2232. Corresponding to the first attachment point, at which the wirelessterminal has a connection, the wireless terminal outputs received 1^(st)uplink loading factor information 2212. Corresponding to the secondattachment point the wireless terminal may or may not have been able todetect and recover an uplink loading factor. In step 2214, if thewireless terminal has detected and recovered an uplink loading factorcorresponding to the second attachment point the wireless terminalforwards the received 2^(nd) uplink loading factor information 2216 tobe used in step 2232. However, if the wireless terminal has not detectedand recovered an uplink loading factor corresponding to the secondattachment point, the wireless terminal sets the 2^(nd) uplink loadingfactor to a default value, e.g., a value of 1, in step 2218, the defaultvalue to be used in step 2232. Corresponding to the third attachmentpoint the wireless terminal may or may not have been able to detect andrecover an uplink loading factor. In step 2220, if the wireless terminalhas detected and recovered an uplink loading factor corresponding to thethird attachment point the wireless terminal forwards the received3^(rd) uplink loading factor information 2222 to be used in step 2232.However, if the wireless terminal has not detected and recovered anuplink loading factor corresponding to the third attachment point, thewireless terminal sets the 3^(rd) uplink loading factor to a defaultvalue, e.g., a value of 1, in step 2224, the default value to be used instep 2232.

In step 2232, the wireless terminal generates an uplink interferencereport based on the measurement of the first signal, a first receiveduplink loading factor corresponding to the first attachment point, andusing the results of the second measurement. Step 2232 includes step2234, in which the wireless terminal determines a ratio of first andsecond values, said first value being a function of a product of the1^(st) loading factor and the result of the first signal measurement andwherein the second value is a function of the second result of thesecond measurement. In some embodiments, the second value is also afunction of a product of a second loading factor corresponding to thesecond attachment point and the result of the second signal measurement.

In some embodiments, e.g., some embodiments where three or more receivedsignals from three different attachment points are used in generating aninterference report, step 2234 includes step 2236. In step 2236 thewireless terminal uses the result of the third measurement to generatethe second value. Step 2236 includes sub-step 2238 and sub-step 2240,one of which is performed to generate an interference report. In someembodiments, at different times different ones of sub-steps 2238 and2240 are used to generate the interference report. In sub-step 2238, thewireless terminal sums third and fourth values, said third value being afunction of the result of the second signal measurement, said fourthvalue being a function of the result of the third signal measurement. Insub-step 2240, the wireless terminal sets the second value to be themaximum of third and fourth values, said third value being a function ofthe result of the second signal measurement, said fourth value being afunction of the result of the third signal measurement.

Operation proceeds from step 2232 to step 2242. In step 2242, thewireless terminal transmits the generated uplink interference reportfrom step 2232.

In some embodiments the first and second signals are OFDM signals. Insome other embodiments, the first and second signals are CDMA signals.

In some embodiments, for at least some interference reports, the firstvalue is generated according to the following equation: b₀PB₀; and thesecond value is generated according to the following equation:b₁PB₁+b₂PB₂; where b₀ is the loading factor corresponding to the firstattachment point; wherein PB₀ is the measured power of a received beaconsignal from the first attachment point; wherein b₁ is a loading factorcorresponding to the second attachment point; wherein PB₁ is themeasured power of a received beacon signal from the second attachmentpoint; wherein b₂ is a loading factor corresponding to the thirdattachment point; and wherein PB₂ is the measured power of a receivedbeacon signal from the third attachment point.

In some embodiments, for at least some interference reports, the firstvalue is generated according to the following equation: b₀PB₀; and thesecond value is generated according to the following equation: MAX(b₁PB₁, b₂PB₂); where b₀ is the loading factor corresponding to thefirst attachment point; wherein PB₀ is the measured power of a receivedbeacon signal from the first attachment point; wherein b₁ is a loadingfactor corresponding to the second attachment point; wherein PB₁ is themeasured power of a received beacon signal from the second attachmentpoint; wherein b₂ is a loading factor corresponding to the thirdattachment point; and wherein PB₂ is the measured power of a receivedbeacon signal from the third attachment point.

FIG. 23 is a drawing of an exemplary wireless terminal 2300 implementedin accordance with various embodiments. Exemplary wireless terminal 2300includes a receiver module 2302, a transmitter module 2304, a processor2306, user I/O devices 2308, and a memory 2310 coupled together via abus 2312 over which the various elements may interchange data andinformation. Memory 2310 includes routines 2318 and data/information2320. The processor 2306, e.g., a CPU, executes the routines 2318 anduses the data/information 2320 in memory 2310 to control the operationof the wireless terminal 2300 and implement methods.

Receiver module 2302, e.g., an OFDM receiver, is coupled to receiveantenna 2314 via which the wireless terminal 2300 receives downlinksignals from base station attachment points, said downlink signalsincluding broadcast signals conveying uplink attachment point loadingfactors, beacon signals, and pilot signals. Transmitter module 2304,e.g., an OFDM transmitter, is coupled to transmit antenna 2316 via whichthe wireless terminal 2300 transmits uplink signals to base stationattachment points, said uplink signals including generated interferencereports, e.g., beacon ratio reports communicated via dedicated controlchannel segments. In some embodiments, the same antenna is used forreceiver and transmitter, e.g., in conjunction with a duplex module. Insome other embodiments, the transmitter module 2304 is a CDMAtransmitter and the receiver module 2302 is a CDMA receiver. In someembodiments the transmitter module 2304 and/or receiver module 2302support both OFDM and CDMA signaling.

I/O devices 2308 include, e.g., microphone, keyboard, keypad, switches,camera, speaker, display, etc. I/O devices 2308 allow a user of WT 2300to input data/information, access output data/information, controlapplications, and control at least some functions of the WT 2300, e.g.,initiate a communications session.

Routines 2318 include communications routines 2322 and wireless terminalcontrol routines 2324. The communications routines 2322 implementvarious communications protocols used by the wireless terminal 2300. Thewireless terminal control routines 2324 include an uplink loading factorsignal monitoring module 2326, a loading factor determination module2328, a first measurement module 2330, a second measurement module 2332,and an interference report generation module 2334.

The uplink loading factor signal monitoring module 2326 detects receivedbroadcast signals communicating at least one uplink loading factor, eachbroadcast uplink loading factor corresponding to an attachment point.The first measurement module 2330 measures received signals of a firsttype, e.g., first measurement module 2330 is a beacon signal measurementmodule which measures received beacon signals. The first signalmeasurement module 2330 includes a signal power measurement module 2331which measures the power of received beacon signals. The secondmeasurement module 2332 measures received signals of a second type,e.g., second measurement module 2332 is a pilot signal measurementmodule which measures received pilot signals. The second measurementmodule 2332 includes a signal power measurement module 2333 whichmeasures the power of received pilot signals.

Interference report generation module 2334 generates an uplinkinterference report based on a measurement of a first received signal,e.g., a received beacon or pilot signal, and a first received uplinkloading factor corresponding to a first attachment point. In variousembodiments, the interference report generation module uses themeasurement of a second signal, e.g., a received beacon or pilot signal,from a second attachment point to generate an uplink interferencereport. The interference report generation module includes a first valuegeneration module 2336, a second value generation module 2338, a summingmodule 2342, and a maximum value selector module 2344. The second valuegeneration module 2338 includes a multiplier module 2340.

The first value generation module 2336 generates a first value 2384 as afunction of a product of a first loading factor and the result of afirst signal measurement. For example, the first loading factor maycorrespond to the attachment point of the current connection being usedby the wireless terminal as it point of attachment, and the first signalmay be a received beacon or pilot signal from the attachment point ofthe current connection.

Second value generation module 2338 generates a second value 2386 as afunction of a result of a second measurement, e.g., the result of ameasurement of a received beacon or pilot signal from a differentattachment point than the one used by the first value generation module.For example, the second signal may be sourced from an attachment pointin an adjacent sector and/or adjacent cell to the current servingattachment point.

Multiplier module 2340 is used for generating a product of a secondloading factor corresponding to a second attachment point and the resultof the second signal measurement.

In some embodiments, the interference report generation module 2334generates at least one uplink interference report using the result of athird measurement of a third signal from a third attachment point togenerate said second value.

Summing module 2342 sums third and fourth values (2388, 2390) said thirdvalue being a function of the result of the second signal measurement,said fourth value being a result function of the result of the thirdsignal measurement. In some embodiments, for at least some interferencereports, the first value is generated according to the followingequation: b₀PB₀; the second value is generated according to thefollowing equation: b₁PB₁+b₂PB₂; where b₀ is the loading factorcorresponding to the first attachment point; wherein PB₀ is the measuredpower of a received beacon signal from the first attachment point;wherein b₁ is a loading factor corresponding to the second attachmentpoint; wherein PB₁ is the measured power of a received beacon signalfrom the second attachment point; wherein b₂ is a loading factorcorresponding to the third attachment point; and wherein PB₂ is themeasured power of a received beacon signal from the third attachmentpoint.

Maximum value sector module 2344, when utilized, sets the second valueto be the maximum of third and fourth values (2388, 2390), said thirdvalue being a function of the result of the second signal measurement,said fourth value being a function of the result of the third signalmeasurement. In some embodiments, for at least some interferencereports, the first value is generated according to the followingequation: b₀PB₀; and the second value is generated according to thefollowing equation: MAX (b₁PB₁, b₂PB₂); where b₀ is the loading factorcorresponding to the first attachment point; wherein PB₀ is the measuredpower of a received beacon signal from the first attachment point;wherein b₁ is a loading factor corresponding to the second attachmentpoint; wherein PB₁ is the measured power of a received beacon signalfrom the second attachment point; wherein b₂ is a loading factorcorresponding to the third attachment point; and wherein PB₂ is themeasured power of a received beacon signal from the third attachmentpoint.

In some embodiments, for at least some of the interference reportsgenerated at least some of said first, second and third signalmeasurements are measurements of pilot channel signals. In someembodiments, scaling factors are used to relate transmission powers ofpilot signals to transmission powers of beacon signals and/ortransmission powers of pilot signals from one attachment point totransmission powers of pilot signals from a different attachment point.

In some embodiments, the interference report generation module 2344supports the generation of a variety of different types of reports,e.g., specific reports relating a current serving base stationattachment point, to a single identified other base station attachmentpoint, a generic report of a first sub-type relating a current servingbase station to one or more, e.g., a plurality, of other base stationsectors from which signals, e.g., beacons and/or pilots, are receivedand using a summation type function in generating the report, and ageneric report of a second sub-type relating a current serving basestation attachment point to one or more, e.g., a plurality, of otherbase station sectors from which signals, e.g., beacons and/or pilots,are received and using a summation type function in generating thereport.

Loading factor determination module 2328 sets a loading factor to adefault value in the absence of a successfully received loading factorcorresponding to an attachment point of interest. For example, theloading factor determination module 2328 sets a second loading factor toa default value in the absence of a successfully received second loadingfactor from a second attachment point.

Data/information 2320 includes received beacon signal information 2346,received pilot signal information 2348, received uplink loading factorinformation 2350, measured beacon information 2352, measured pilotinformation 2354, default uplink loading factor information 2356, andinterference report information 2358. Received beacon signal information2346 may include received beacon signal information corresponding tovarious attachment points (attachment point 1 information 2360, . . . ,attachment point N information 2362). Received pilot signal information2348 may include received pilot signal information corresponding tovarious attachment points (attachment point 1 information 2364, . . . ,attachment point N information 2366). Received uplink loading factorinformation 2350 may include received uplink loading factor informationcorresponding to various attachment points (attachment point 1information 2368, . . . , attachment point N information 2370). Measuredbeacon signal information 2352 may include measured beacon signalinformation corresponding to various attachment points (attachment point1 information 2372, . . . , attachment point N information 2374).Measured pilot signal information 2354 may include measured pilot signalinformation corresponding to various attachment points (attachment point1 information 2376, . . . , attachment point N information 2378).Default uplink loading factor information 2356 may include defaultuplink loading factor information corresponding to various attachmentpoints (attachment point 1 information 2380, . . . , attachment point Ninformation 2382).

At one given time the mixture of information stored and used ingenerating an uplink interference report may vary from the mixture ofinformation stored at another point in time. For example at one givetime, the wireless terminal may include received pilot signal and beaconsignal information corresponding to attachment point 1, received beaconsignal information corresponding to attachment point 2, received beaconsignal information corresponding to attachment point 3, received uplinkloading factor information corresponding to attachment point 1, receiveduplink loading factor information corresponding to attachment point 2,measured pilot signal information corresponding to attachment point 1,measured beacon signal information corresponding to attachment point 1,measured beacon signal information corresponding to attachment point 2,measured beacon signal information corresponding to attachment point 3,and default uplink loading factor information corresponding toattachment point 3. Continuing with the example at another given time,the wireless terminal may include received pilot signal and beaconsignal information corresponding to attachment point 1, received beaconsignal information corresponding to attachment point 2, received pilotsignal and received beacon signal information corresponding toattachment point 3, received uplink loading factor informationcorresponding to attachment point 1, received uplink loading factorinformation corresponding to attachment point 3, measured pilot signalinformation corresponding to attachment point 1, measured beacon signalinformation corresponding to attachment point 1, measured beacon signalinformation corresponding to attachment point 2, measured pilot signalinformation corresponding to attachment point 3, measured beacon signalinformation corresponding to attachment point 3, and default uplinkloading factor information corresponding to attachment point 2.

Interference report information 2358 includes a first value 2384, asecond value 2386, a third value 2388, a fourth value 2390, a sum value2392, a max value 2394, a determined ratio 2396, and a quantized reportvalue 2398. First value 2384 is a result of operations of first valuegeneration module 2366, while second value 2386 is a result ofoperations of second value generation module 2338. Third and fourthvalues (2388, 2390) are intermediate processing values used ingenerating at least some interference reports, e.g., interferencereports considering information from three or more different attachmentpoints. Sum value 2392 is a result of an operation by summing module2342. Max value 2394 is a result of an operation of maximum value sectormodule 2344. Determined ratio is a determined ratio of first and secondvalues determined by interference report generation module. Quantizedreport value 2398 is a value which is one of a plurality of quantizedlevels to be communicated in an interference report to communicate adetermined ratio 2396.

FIG. 24 comprising the combination of FIG. 24A and FIG. 24B is aflowchart 2400 of an exemplary method of operating a wireless terminal.The exemplary method starts in step 2402, where the wireless terminal ispowered on and initialized. Operation proceeds from start step 2402 tosteps 2404, 2406 and 2408.

In step 2404, the wireless terminal receives base station identificationinformation including a control signal communicating a locally uniquebase station identifier at which a second attachment point is located.In step 2406, the wireless terminal receives a first signal, e.g., abeacon signal or a pilot signal, from a first attachment point withwhich said wireless terminal has a connection. In step 2408, thewireless terminal receives signals, e.g., beacon and/or pilot signals,from one or more attachment points in addition to said first attachmentpoint. Step 2406 includes sub-step 2412, in which the wireless terminalreceives a second signal, e.g., a beacon or pilot signal, from thesecond attachment point, said received base station identificationinformation, from step 2404, corresponding to the second attachmentpoint. Step 2406, at various times includes one or more additionalsub-steps, corresponding to received signals, e.g., received beaconand/or pilot signals, from additional attachment points. For example, insub-step 2414, the wireless terminal receives an Nth signal, e.g., abeacon or pilot signal, from an Nth attachment point.

Operation proceeds from step 2406 to step 2410. In step 2410 thewireless terminal performs a first measurement on the received firstsignal, e.g., a power measurement of the received first signal.Operation proceeds from sub-step 2412 to step 2416. In step 2416 thewireless terminal performs a second measurement on the received secondsignal, e.g., a power measurement of the received first signal.Operation proceeds from sub-step 2414 to step 2418. In step 2418 thewireless terminal performs an Nth measurement on the received Nthsignal, e.g., a power measurement of the received Nth signal.

In some embodiments, e.g. some embodiments using multi-sector basestations, operation proceeds from step 2416 to step 2420. In otherembodiments, e.g., some embodiments with a single sector base stationper cell, operation proceeds from step 2416 to step 2422.

In step 2420, the wireless terminal determines a sector identifiercorresponding to the received base station identifier from the time atwhich said control signal is received, said sector identifieridentifying a sector which serves as the second attachment point. Insome embodiments, the sector identifier is determined as a function ofstored timing structure information and a time slot in the recurringstructure to which said received signal time corresponds.

Operation proceeds from step 2420 to step 2422. In step 2422, thewireless terminal identifies the second signal, from among the one ormore received signals of step 2408 corresponding to different attachmentpoints, as a function of the received base station identificationinformation. Operation proceeds from step 2422 to step 2424.

In step 2424, the wireless terminal generates a report, e.g., aninterference report such as a specific interference report, based on themeasurement of the first and second signal. In some embodiments, thereport is an interference report which is a ratio of a first value to asecond value, the first value being a function of the measured power ofthe first signal and the second value being a function of the measuredpower of the second signal. Operation proceeds from step 2424 to step2426. In step 2426, the wireless terminal determines a transmission timeat which the generated report is to be transmitted according to apredetermined function that uses the time at which the control signal isreceived as a transmission time control input. In some embodiments, thepredetermined function determines the transmission time to be at a timecorresponding to a fixed predetermined offset from the time at which thecontrol signal is received.

Operation proceeds from step 2426 to step 2428, where the generatedreport, e.g., the generated specific type interference report relatingtwo attachment points, is transmitted. Operation proceeds from step 2428via connecting node A 2430 to step 2432. In step 2432, the wirelessterminal receives a control signal indicating that an interferencereport is to be based on signals received from a plurality of differenttransmitters in addition to said first attachment point. Operationproceeds from step 2432 to step 2434. In step 2434, the wirelessterminal performs measurements on the plurality of signals received fromthe plurality of different transmitters and from the first attachmentpoint. Operation proceeds from step 2434 to step 2436.

In step 2436, the wireless terminal generates a report, e.g., aninterference report which is based on one of the sum and maximum ofvalues derived from the results of said signals from differenttransmitters. For example, the generated interference report may be ageneric type interference report of a first sub-type using a summationfunction in generating the report. Alternatively, the generatedinterference report may be a generic interference report of a secondsub-type using a maximum function in generating the report. In someembodiments, step 2436 includes sub-step 2438. In sub-step 2438, thewireless terminal determines whether the interference report is to bebased on the sum or maximum as a function of timing structureinformation. Operation proceeds from step 2436 to step 2440, where thewireless terminal transmits the generated report from step 2436.

In some embodiments, the step of receiving base station identificationinformation, step 2404, includes receiving a broadcast signal from thefirst attachment point, said broadcast signal being used to controlmultiple wireless terminals. In this way signaling overhead is reducedfrom the amount that would otherwise be needed to individually signalsuch base station identification information individually to each of thewireless terminals being serviced by the first attachment point.

FIG. 25, comprising the combination of FIG. 25A and FIG. 25B is aflowchart 2500 of an exemplary method of operating a wireless terminalin accordance with various embodiments. Operation starts in step 2502,where the wireless terminal is powered on and initialized. Operationproceeds from start step 2502 to: step 2504, step 2506, step 2508, step2533 via connecting node A 2532, step 2535 via connecting node B 2534,step 2544 via connecting node C 2536, and, in some embodiments, step2546 via connecting node D 2538.

In step 2504, the wireless terminal receives, on an ongoing basis,broadcast control signals which include request for interface reportinformation from an attachment point of a current connection. For areceived request, operation proceeds from step 2504 to step 2510. Instep 2510, the wireless terminal determines from received request forinterference report information the type of interference reportrequested, specific or generic, and for a specific type of report alocally unique cell identifier corresponding to an attachment point.Step 2510 includes sub-step 2512. In sub-step 2512, if the receivedrequest value is a zero, the wireless terminal determines that therequested report type is a generic report as indicated by reporttype=generic output 2514. In sub-step 2512, if the received value isnon-zero, the wireless terminal determines that the requested reporttype is a specific report as indicated by report type=specific output2516. In addition, if the received value is non-zero, the wirelessterminal sets the cell identifier equal to the received request value,e.g., the positive request value being one of a potential set ofpositive integers each different potential positive integercorresponding to a different pilot channel slope value. The output cellidentifier value is represented by output 2518.

In step 2506, the wireless terminal receives, on an ongoing basis,beacon and/or pilot signals from the current attachment point. Operationproceeds from step 2506 to step 2520. In step 2520, the wirelessterminal measures the strengths of received beacon and/or pilot signalsfrom the current attachment point outputting current attachment pointreceived signal strength information 2526.

In step 2508, the wireless terminal receives, on an ongoing basis,beacon and/or pilot signals from additional attachment point(s).Operation proceeds from step 2508 to step 2522, and at some times tostep 2524. In step 2522, the wireless terminal measures the strengths ofreceived beacon and/or pilot signals from an additional attachment pointoutputting 1^(st) additional attachment point received signal strengthinformation 2528. In step 2524, the wireless terminal measures thestrengths of received beacon and/or pilot signals from a differentadditional attachment point outputting N^(th) additional attachmentpoint received signal strength information 2530.

Returning to step 2533, in step 2533 the wireless terminal receiveswireless terminal On state identification information associated with adedicated control channel structure, said dedicated control channelstructure including reporting times in the recurring structure forinterference reports to be transmitted by the wireless terminal to thecurrent attachment point. Step 2533 outputs information identifyingsegments to be used for interference reports 2540.

Returning to step 2535, in step 2535 the wireless terminal tracks, on anongoing basis, timing in a recurring timing structure being used by thecurrent connection and output current time information 2542, e.g., indexinformation in a recurring OFDM timing structure.

Returning to step 2544, in step 2544 the wireless terminal determines,on an ongoing basis, is an interference report to be communicated. Step2544 uses as input current time information 2542 and informationidentifying segments for interference reports 2540 as well as timingstructure information pertaining to the current connection. If it isdetermined in step 2544 that an interference report is to communicated,operation proceeds from step 2544 to step 2552, step 2558 and step 2566.

In step 2552, the wireless terminal determines does the time correspondto ^(st) or 2^(nd) type generic report. If the time corresponds to a1^(st) type of generic report, generic report sub-type=summationfunction type as indicated by output 2554; however if the timecorresponds to a 2^(nd) type generic report, generic report sub-type=maxfunction type as indicated by output 2556.

In step 2558, the wireless terminal determines which sector type thetime corresponds to with respect to the attachment point for a specifictype report. For example, in one exemplary embodiment, a recurringtiming structure is subdivided into beaconslots, there are threedifferent sector types, and the sector type associated with an indexedbeaconslot alternates between the three different sector types. (SeeFIG. 18.) The output of step 2558 is one of sector type=sector type 02560, sector type=sector type 1 2562, and sector type=sector type 22564.

In some embodiments, the wireless terminal uses uplink loading factorinformation in calculating an interference report and includes steps2546 and 2548. In step 2546, the wireless terminal monitors andreceives, on an ongoing basis, uplink loading factor informationcorresponding to attachment points. Operation proceeds from step 2546 tostep 2548, in which the wireless terminal applies default uplink loadingfactor values for attachment points of interest for which uplink loadingfactor information has not been received. Uplink loading factorinformation 2550, received and/or default information, is output formsteps 2546 and/or 2548.

Returning to step 2556, in step 2556, the wireless terminal generates aninterference report in accordance with the requested report type(specific or generic); in the case of a generic report the report alsobeing in accordance with the report sub-type (summation function type ormax function type); and in the case of a specific report the reportrelates to a specific,identified attachment point, e.g., identified bycell identifier/sector type identifier combination, and to the currentattachment point. Inputs available to step 2566 include at least someof: report type information 2568, generic report sub-type information2570, cell identification information 2518, sector type information2574, information relating beacon to pilot transmission power levels,current attachment point received strength information 2526, ^(st)additional attachment point received strength information 2528, Nthadditional attachment point received strength information 2530 anduplink loading factor information 2550. Report type information 2568identifies whether the report is to be a generic or specific report andis one of outputs 2514 and 2516. Generic report sub-type information2570 identifies whether the report if it is a generic report is to use asummation function in generating the report or a maximum function ingenerating the report. Generic report sub-type information 2570 is oneof outputs 2554 and 2556. Cell ID information 2518 is the received valuefrom the received report request control signal. Sector type information2574 is one of the outputs 2560, 2562 and 2564. Information relatingbeacon/pilot transmission power levels includes power tier levelinformation and other gain information relating the transmission powerof a beacon signal to the transmission power of a pilot signal for anattachment point under consideration, as well as information relatingtransmission power levels between different attachment points.

For a generic report, the wireless terminal uses the received strengthinformation 2526, 2528, . . . , 2530 to generate a interference report,the sub-type of report summation function type or max function typebeing determined by information 2570. For a specific type report thewireless terminal generates a report relating current attachment pointreceived strength information 2526 to one of (1^(st) additionalattachment point received strength information 2528, . . . , Nthadditional attachment point received strength information 2530), the onebeing determined by the identify of the additional attachment pointwhich corresponds to the combination of the cell identifier 2518 andsector type 2574.

Operation proceeds from step 2566 to step 2584, where the wirelessterminal transmits the generated interference report to the currentattachment point.

FIG. 26 is a drawing of a table 2600 illustrating exemplary interferencereport signal usage and report computations in accordance with variousembodiments. First column 2602 lists descriptive information pertainingto an interference report communicating a ratio of a first to a secondvalue. Second column 2504 lists first value; third column 2606 listssecond value; fourth column 2608 lists third value; fifth column 2510lists fourth value; sixth column 2612 lists 1^(st) signal type; seventhcolumn 2614 lists 2^(nd) signal type; eighth column 2616 lists 3^(rd)signal type.

Each row (2618, 2620, 2622, 2624, 2626, 2628, 2630, 2632, 2632 describesa different report. Row 2618 pertains to a specific interference reportusing received beacon signal power measurements. Row 2620 pertains to aspecific interference report using received pilot signal powermeasurements. Row 2622 pertains to a specific interference report usingreceived pilot and beacon signal power measurements. Row 2624 pertainsto a 1^(st) sub-type of generic interference report using receivedbeacon signal power measurements. Row 2626 pertains to a 2^(nd) sub-typeof interference report using received beacon signal power measurements.Row 2628 pertains to a 1^(st) sub-type of generic interference reportusing received pilot signal power measurements. Row 2630 pertains to a2^(nd) sub-type of interference report using received pilot signal powermeasurements. Row 2632 pertains to a 1^(st) sub-type of genericinterference report using received pilot and beacon signal powermeasurements. Row 2630 pertains to a 2^(nd) sub-type of interferencereport using received pilot and beacon signal power measurements.

In table 2600, b₀ is the loading factor corresponding to the firstattachment point; PB₀ is the measured power of a received beacon signalfrom the first attachment point; PP₀ is the measured power of a receivedpilot signal from the first attachment point; b1 is the loading factorcorresponding to the second attachment point; PB₁ is the measured powerof a received beacon signal from the second attachment point; PP₁ is themeasured power of a received pilot signal from the second attachmentpoint; b₂ is the loading factor corresponding to the third attachmentpoint; PB₂ is the measured power of a received beacon signal from thesecond attachment point; PP₂ is the measured power of a received pilotsignal from the second attachment point. For example, the firstattachment point may correspond to the current serving attachment pointto which the interference report is communicated, and the second andthird attachment point may correspond to other local attachment pointsin the system. K is a scaling factor relating the transmission powerstrength of a beacon signal to the transmission power strength of apilot signal.

In this example, it may be assumed that the beacon signal aretransmitted at the same transmission power level from attachment points1, 2, and 3; it may be also assumed that the pilot, signal aretransmitted at the same transmission power level from attachment points1, 2, and 3.

In some embodiments, the beacon signals are transmitted at the sametransmission power irrespective of the attachment point, while thetransmission power level of the pilot signal varies as a function of theattachment point. In some such embodiments, different power tier levelsare used for different attachment points and scaling factors relatingthe power tier levels of the different attachment points may be used inthe interference report calculations.

Table 2600 describes exemplary generic reports using information fromthree different attachment points; the formulas used may be extended toinclude using received power measurements from additional attachmentpoints.

FIG. 27 is a drawing of an exemplary wireless terminal 2700 implementedin accordance with various embodiments. Exemplary wireless terminal 2700includes a receiver module 2702, a transmitter module 2704, a processor2706, I/O devices 2708, and memory 2710 coupled together via a bus 2712over which the various elements may interchange data and information.Memory 2710 includes routines 2718 and data/information 2720. Theprocessor 2706, e.g., a CPU, executes the routines 2718 and uses thedata/information 2720 in memory 2710 to control the operation of thewireless terminal 2700 and implement methods of the invention.

The receiver module 2702, e.g., an OFDM receiver, is coupled to receiveantenna 2714 via which the wireless terminal receives downlink signalsfrom base station attachment points. The downlink signals includevarious broadcast signals including beacon signals, pilot signals, andbase station identification information, e.g., a locally unique cellidentifier corresponding to an attachment point to be used in a specifictype report, and request interference report type information, e.g.,information distinguishing between a specific type interference reportand a generic type interference report. In some embodiments, the locallyunique base station identifier is of a sectorized base station at whichthe second attachment point is located. Receiver module 2702 receives aplurality of signals from multiple attachment points, said plurality ofsignals including a second signal, e.g., said second signal being abeacon or pilot signal from a second attachment point, said secondattachment being in addition to a first attachment point, e.g., acurrent connection attachment point.

Transmitter module 2704, e.g., an OFDM transmitter, is coupled totransmit antenna 2716 via which the wireless terminal transmits uplinksignals including generated interference reports, e.g., a beacon ratioreport communicated over a dedicated control channel. In variousembodiments, the receiver module 2702 and transmitter module 2704 usethe same antenna, e.g., in conjunction with a duplex module.

Routines 2718 include communications routines 2722 and wireless terminalcontrol routines 2724. Wireless terminal control routines 2724 include amonitoring module 2726, a first measurement module 2728, e.g., a beaconsignal measurement module, a second measurement module 2732, e.g., apilot signal measurement module, an interference report generationmodule 2734, a signal identification module 2736, a transmission timedetermination module 2738, a sector type determination module 2740, anda control module 2742. The first measurementh module 2728 includes asignal power measurement module 2331. The second measurement module 2732includes a signal power measurement module 2333.

Communications module 2722 implements various communications protocolsused by the wireless terminal 2700. Monitoring module 2726 detectsbroadcast base station identification information, e.g., a locallyunique base station identifier such as a cell slope value correspondingto a base station attachment point from which received signal strengthmeasurements of beacons and/or pilots are to be obtained and used in aspecific interference report that is being requested to be communicatedover the uplink. First measurement module 2728 measures received signalsof a first type, e.g., beacon signals. Second signal measurement module2732 measures signals of a second type, e.g. pilot signals. Interferencereport generation module 2732 generates a report based on a measurementof a first received signal and a measurement of a second receivedsignal, said first received signal being from a first attachment pointwith which said wireless terminal has a connection, said second receivedsignal being from a second attachment point corresponding to basestation identification information detected by said monitoring module2726.

Signal identification module 2736 identifies the second signal from aplurality of signals as a function of detected broadcast base stationidentification information. Thus signal identification uses informationfrom monitoring module 2726 in identifying the second signal. In someembodiments, the detected broadcast base station identificationinformation is detected in a broadcast signal from the first attachmentpoint, said broadcast signal being used to control multiple wirelessterminals.

Transmission time determination module 2738 determines a transmissiontime at which a generated interference report is to be transmittedaccording to a predetermined function that uses the time at which acontrol signal including base station identification information isreceived as a transmission time control input. In some embodiments, thepredetermined function determines the transmission time to be at a timecorresponding to a fixed predetermined offset from the time at which thecontrol signal is received.

Sector type determination module 2740 determines a sector identifiercorresponding to a received base station identifier from the time atwhich the control signal is received, said sector identifier identifyinga sector which serves as a second attachment point. In some embodiments,the sector identifier is determined as a function of stored timingstructure information and a time slot in a recurring structure to whichsaid received signal time corresponds.

Control module 2742 controls the interference report generation module2734 to generate reports of different types in response to differentreceived control signals, said different types of reports including atleast a first type report and a second type report, said first type ofreport communicating a ratio or first and second values, one of saidfirst and second values corresponding to a measurement of a signal froma current connection attachment point and the other one of said firstand second values of an attachment point specified to the wirelessterminal by the current connection attachment point, e.g., the currentconnection attachment point selects which of the other potentialattachment points signals are to be used in calculating the interferencereport. For example, the first type of report may be a specific beaconratio report and the second type of report may be a generic beacon ratioreport. One received control signal, e.g., a value of 0 in ainterference report request broadcast signal may signal that a genericreport is requested to be communicated; another received control signal,e.g., a positive integer value in an interference report requestbroadcast signal may signify that a specific type of beacon ratio reportis being requested, with the positive integer value being used inidentifying the second attachment point.

In some embodiments, the second type of report, e.g., a generic beaconratio report, is generated using a maximum or summation function inprocessing signal measurement information corresponding to one or moresignals.

In various embodiments, the interference report is an interferencereport which is a ratio of a first value to a second value, the firstvalue being a function of the measured power of a first signal, e.g., abeacon or pilot signal from a first attachment point which is thecurrent connection, and the second value being a function of themeasured power of a second signal, e.g., a beacon or pilot signal fromanother base station attachment point, e.g., an adjacent cell and/orsector attachment point using the same carrier and/or tone block.

Data/information 2720 includes stored timing structure information 2744,detected broadcast base station identification information 2746, firstreceived signal measurement information 2748, second received signalmeasurement information 2750, generated interference report information2752, current attachment point connection ID information 2754,attachment point corresponding to detected base station identificationinformation 2756, control signal reception time information 2758,received locally unique base station identification 2760, identified2^(nd) attachment point sector type 2762, determined time slotinformation 2764, 1sst type interference report, e.g., specificinterference report, information 2766, and 2^(nd) type interferencereport, e.g., generic report, information 2768.

While described in the context of an OFDM system, the methods andapparatus of various embodiments, are applicable to a wide range ofcommunications systems including many non-OFDM and/or non-cellularsystems.

In various embodiments nodes described herein are implemented using oneor more modules to perform the steps corresponding to one or moremethods, for example, signal processing, beacon generation, beacondetection, beacon measuring, connection comparisons, connectionimplementations. In some embodiments various features are implementedusing modules. Such modules may be implemented using software, hardwareor a combination of software and hardware. Many of the above describedmethods or method steps can be implemented using machine executableinstructions, such as software, included in a machine readable mediumsuch as a memory device, e.g., RAM, floppy disk, etc. to control amachine, e.g., general purpose computer with or without additionalhardware, to implement all or portions of the above described methods,e.g., in one or more nodes. Accordingly, among other things, variousembodiments are directed to a machine-readable medium including machineexecutable instructions for causing a machine, e.g., processor andassociated hardware, to perform one or more of the steps of theabove-described method(s).

Numerous additional variations on the methods and apparatus describedabove will be apparent to those skilled in the art in view of the abovedescriptions. Such variations are to be considered within scope. Themethods and apparatus of various embodiments may be, and in variousembodiments are, used with CDMA, orthogonal frequency divisionmultiplexing (OFDM), and/or various other types of communicationstechniques which may be used to provide wireless communications linksbetween access nodes and mobile nodes. In some embodiments the accessnodes are implemented as base stations which establish communicationslinks with mobile nodes using OFDM and/or CDMA. In various embodimentsthe mobile nodes are implemented as notebook computers, personal dataassistants (PDAs), or other portable devices includingreceiver/transmitter circuits and logic and/or routines, forimplementing the methods of various embodiments.

What is claimed is:
 1. A method of operating a wireless terminalcomprising: monitoring to detect received broadcast signalscommunicating at least one uplink loading factor, each broadcast uplinkloading factor corresponding to an attachment point; receiving a firstsignal from a first attachment point; performing a first measurement onthe received first signal; receiving a second signal from a secondattachment point; performing a second measurement on the received secondsignal; wherein said first and second measurements are signal powermeasurements; generating an uplink interference report based on themeasurement of the first signal, the measurement of the second signaland a first received uplink loading factor corresponding to said firstattachment point, said uplink interference report communicating a ratioof first and second values, said first value being a function of aproduct of said first loading factor and a result of said first signalmeasurement and wherein said second value is a function of a result ofthe second measurement; and transmitting said generated uplinkinterference report.
 2. The method of claim 1, wherein said first signalis a beacon or pilot signal; and wherein said second signal is a beaconor pilot signal.
 3. The method of claim 1 wherein the first and secondsignals are OFDM signals.
 4. The method of claim 1, wherein said secondvalue is also a function of a product of a second loading factorcorresponding to said second attachment point and the result of saidsecond signal measurement.
 5. The method of claim 4, further comprising:receiving said second loading factor prior to generating said uplinkinterference report.
 6. The method of claim 4, further comprising:setting said second loading factor to default value.
 7. The method ofclaim 1, further comprising: receiving a third signal from a thirdattachment point; performing a third measurement on the received thirdsignal; and wherein generating an uplink interference report furtherincludes using the result of the third measurement to generate saidsecond value.
 8. The method of claim 7, wherein using the result of thethird measurement to generate said second value include: summing thirdand fourth values, said third value being a function of the result ofthe second signal measurement, said fourth value being a function of theresult of the third signal measurement.
 9. The method of claim 8,wherein said first value is generated according to the followingequation: b₀PB₀; and wherein said second value is generated according tothe following equation: b₁PB₁+b₂PB₂; where b₀ is the loading factorcorresponding to the first attachment point; wherein PB₀ is the measuredpower of a received beacon signal from the first attachment point;wherein b₁ is a loading factor corresponding to the second attachmentpoint; wherein PB₁ is the measured power of a received beacon signalfrom the second attachment point; wherein b₂ is a loading factorcorresponding to the third attachment point; and wherein PB₂ is themeasured power of a received beacon signal from the third attachmentpoint.
 10. The method of claim 7, wherein using the result of the thirdmeasurement to generate said second value include: setting the secondvalue to be the maximum of third and fourth values, said third valuebeing a function of the result of the second signal measurement, saidfourth value being a function of the result of the third signalmeasurement.
 11. The method of claim 10, wherein said first value isgenerated according to the following equation: b₀PB₀; and wherein saidsecond value is generated according to the following equation:MAX(b₁PB₁, b₂PB₂); where b₀ is the loading factor corresponding to thefirst attachment point; wherein PB₀ is the measured power of a receivedbeacon signal from the first attachment point; wherein b₁ is a loadingfactor corresponding to the second attachment point; wherein PB₁ is themeasured power of a received beacon signal from the second attachmentpoint; wherein b₂ is a loading factor corresponding to the thirdattachment point; and wherein PB₂ is the measured power of a receivedbeacon signal from the third attachment point.
 12. A wireless terminalcomprising: a monitoring module for detecting received broadcast signalscommunicating at least one uplink loading factor, each broadcast uplinkloading factor corresponding to an attachment point; a first measurementmodule including a signal power measurement module for measuring powerof received signals of a first type from a first attachment point; asecond measurement module including a signal power measurement modulefor measuring power of received signals of a second type; a reportgeneration module for generating an uplink interference report based ona power measurement of a first received signal from the first attachmentpoint, a power measurement of a second signal from a second attachmentpoint; and a first received uplink loading factor corresponding to afirst attachment point, said uplink interference report communicating aratio of first and second values, said report generation moduleincluding: i) a first value generation module for generating said firstvalue as a function of a product of said first loading factor and aresult of said power measurement of the first signal; and ii) a secondvalue generation module for generating said second value as a functionof a result of the power measurement of the second signal from thesecond attachment point; and a transmitter for transmitting generateduplink interference reports.
 13. The wireless terminal of claim 12,wherein said first signal is a beacon or pilot signal; and wherein saidsecond signal is a beacon or pilot signal.
 14. The wireless terminal ofclaim 12, wherein said second value generation module includes amultiplier module for generating a product of a second loading factorcorresponding to said second attachment point and the result of saidsecond signal measurement.
 15. The wireless terminal of claim 14,further comprising: a loading factor determination module for settingsaid second loading factor to a default value in the absence of asuccessfully received second loading factor from said second attachmentpoint.
 16. A wireless terminal comprising: means for detecting receivedbroadcast signals communicating at least one uplink loading factor, eachbroadcast uplink loading factor corresponding to an attachment point;means for measuring power of received signals of a first type from afirst attachment point; means for measuring power of received signals ofa second type; means for generating an uplink interference report basedon a power measurement of a first received signal from the firstattachment point, a power measurement of a second signal from a secondattachment point, and a first received uplink loading factorcorresponding to a first attachment point, wherein said up inkinterference report communicates a ratio of first and second values,said means for generating an uplink interference report including: i)means for generating said first value as a function of a product of saidfirst loading factor and a result of the power measurement of said firstsignal: and ii) means for generating said second value as a function ofa result of the power measurement of the second signal; and means fortransmitting generated uplink interference reports.
 17. The wirelessterminal of claim 16, wherein said first signal is a beacon or pilotsignal; and wherein said second signal is a beacon or pilot signal. 18.The wireless terminal of claim 16, wherein the first and second signalsare CDMA signals.
 19. The wireless terminal of claim 16, wherein thefirst and second signals are OFDM signals.
 20. The wireless terminal ofclaim 16, wherein said means for generating said second value includesmeans for generating a product of a second loading factor correspondingto said second attachment point and the result of said second signalmeasurement.
 21. The wireless terminal of claim 20, further comprising:means for setting said second loading factor to a default value in theabsence of a successfully received second loading factor from saidsecond attachment point.
 22. The wireless terminal of claim 16, whereinsaid means for generating an uplink interference report generates atleast one uplink interference report using the result of a thirdmeasurement from a third attachment point to generate said second value.23. The wireless of claim 22, wherein said means for generating anuplink interference report includes: means for summing third and fourthvalues, said third value being a function of the result of the secondsignal measurement, said fourth value being a function of the result ofthe third signal measurement.
 24. The wireless terminal of claim 23,wherein said first value is generated according to the followingequation: b₀PB₀; and wherein said second value is generated according tothe following equation: b₁PB₁b₂PB₂; where b₀ is the loading factorcorresponding to the first attachment point; wherein PB₀ is the measuredpower of a received beacon signal from the first attachment point;wherein b₁ is a loading factor corresponding to the second attachmentpoint; wherein PB₁ is the measured power of a received beacon signalfrom the second attachment point; wherein b₂ is a loading factorcorresponding to the third attachment point; and wherein PB₂ is themeasured power of a received beacon signal from the third attachmentpoint.
 25. The wireless terminal of claim 22, wherein said means forgenerating an uplink interference report includes: means for setting thesecond value to be the maximum of third and fourth values, said thirdvalue being a function of the result of the second signal measurement,said fourth value being a function of the result of the third signalmeasurement.
 26. The wireless terminal of claim 25, wherein said firstvalue is generated according to the following equation: b₀PB₀; andwherein said second value is generated according to the followingequation: MAX(b₁PB₁, b₂PB₂); where b₀ is the loading factorcorresponding to the first attachment point; wherein PB₀ is the measuredpower of a received beacon signal from the first attachment point;wherein b₁ is a loading factor corresponding to the second attachmentpoint; wherein PB₁ is the measured power of a received beacon signalfrom the second attachment point; wherein b₂ is a loading factorcorresponding to the third attachment point; and wherein PB₂ is themeasured power of a received beacon signal from the third attachmentpoint.
 27. A non-transitory computer readable medium embodying machineexecutable instructions for implementing a method of operating awireless terminal, the method comprising: monitoring to detect receivedbroadcast signals communicating at least one uplink loading factor, eachbroadcast uplink loading factor corresponding to an attachment point;receiving a first signal from a first attachment point; performing afirst measurement on the received first signal; receiving a secondsignal from a second attachment point; performing a second measurementon the received second signal; wherein said first and secondmeasurements are signal power measurements; generating an uplinkinterference report based on the measurement of the first signal, themeasurement of the second signal and a first received uplink loadingfactor corresponding to said first attachment point, said uplinkinterference report communicating a ratio of first and second values,said first value being a function of a product of said first loadingfactor and a result of said first signal measurement and wherein saidsecond value is a function of a second result of the second measurement;and transmitting said generated uplink interference report.
 28. Thenon-transitory computer readable medium of claim 27, wherein said firstsignal is a beacon or pilot signal; and wherein said second signal is abeacon or pilot signal.
 29. The non-transitory computer readable mediumof claim 27 wherein the first and second signals are OFDM signals. 30.The non-transitory computer readable medium of claim 29, wherein saidsecond value is also a function of a product of a second loading factorcorresponding to said second attachment point and the result of saidsecond signal measurement.
 31. The non-transitory computer readablemedium of claim 30, further embodying machine executable instructionsfor: receiving said second loading factor prior to generating saiduplink interference report.
 32. The non-transitory computer readablemedium of claim 30, further embodying machine executable instructionsfor: setting said second loading factor to default value.
 33. Anapparatus operable in a communication system, the apparatus comprising:a processor configured to: monitor to detect received broadcast signalscommunicating at least one uplink loading factor, each broadcast uplinkloading factor corresponding to an attachment point; receive a firstsignal from a first attachment point; perform a first measurement on thereceived first signal; receive a second signal from a second attachmentpoint; perform a second measurement on the received second signal, saidfirst and second, measurements being signal power measurements; generatean uplink interference report based on the measurement of the firstsignal, the measurement of the second signal and a first received uplinkloading factor corresponding to said first attachment point, said uplinkinterference report communicating a ratio of first and second values,said first value being a function of a product of said first loadingfactor and a result of said first signal measurement and wherein saidsecond value is a function of a result of the second measurement; andtransmit said generated uplink interference report.
 34. The apparatus ofclaim 33, wherein said first signal is a beacon or pilot signal; andwherein said second signal is a beacon or pilot signal.
 35. Theapparatus of claim 33, wherein said second value is also a function of aproduct of a second loading factor corresponding to said secondattachment point and the result of said second signal measurement. 36.The apparatus of claim 35, wherein the processor is configured to:receive said second loading factor prior to generating said uplinkinterference report.